More typo fixes across the tree

Previously I have made spelling changes as caught by Debian's lintian
tool, which has a short list of common misspellings that it tests for.
This time I decided to run codespell against the source and fix all the
obvious problems it came up with. It also uses a list of misspellings
but it's much larger than lintian's, but also has some false positives
so I went over the list by hand.

The command I used to do check the source was:
git ls-tree -rz --name-only HEAD | xargs -0 codespell -L minimise,errorstring

man/shairport-sync.7

@@ -29,7 +29,7 @@ You should use the configuration file for setting up Shairport Sync. This file i
 
 (Note: Shairport Sync may have been compiled to use a different configuration directory. You can determine which by performing the command \fI$ shairport-sync -V\f1. One of the items in the output string is the value of the \fBsysconfdir\f1, i.e. the System Configuration Directory.)
 
-Within the configuraton file, settings are organised into groups, for example, there is a "general" group of standard settings, and there is an "alsa" group with settings that pertain to the ALSA back end. Here is an example of a typical configuration file:
+Within the configuration file, settings are organised into groups, for example, there is a "general" group of standard settings, and there is an "alsa" group with settings that pertain to the ALSA back end. Here is an example of a typical configuration file:
 
 \fBgeneral = {\f1
 
@@ -90,7 +90,7 @@ Use this to specify the \fIportnumber\f1 shairport-sync uses to listen for servi
 When shairport-sync starts to play audio, it establises three UDP connections to the audio source. Use this setting to specify the starting \fIportnumber\f1 for these three ports. It will pick the first three unused ports starting from \fIportnumber\f1. The default is port 6001.
 .TP
 \fBudp_port_range=\f1\fIrange\f1\fB;\f1
-Use this in conjunction with the prevous setting to specify the \fIrange\f1 of ports that can be checked for availability. Only three ports are needed. The default is 100, thus 100 ports will be checked from port 6001 upwards until three are found.
+Use this in conjunction with the previous setting to specify the \fIrange\f1 of ports that can be checked for availability. Only three ports are needed. The default is 100, thus 100 ports will be checked from port 6001 upwards until three are found.
 .TP
 \fBdrift_tolerance_in_seconds=\f1\fIseconds\f1\fB;\f1
 Allow playback to drift up to \fIseconds\f1 out of exact synchronization before attempting to correct it. The default is 0.002 seconds, i.e. 2 milliseconds. The smaller the tolerance, the more likely it is that overcorrection will occur. Overcorrection is when more corrections (insertions and deletions) are made than are strictly necessary to keep the stream in sync. Use the \fBstatistics\f1 setting to monitor correction levels. Corrections should not greatly exceed net corrections. This setting replaces the deprecated \fBdrift\f1 setting. 
@@ -140,7 +140,7 @@ The \fImode\f1 can be "stereo", "mono", "reverse stereo", "both left" or "both r
 This can be "hammerton" or "apple". This advanced setting allows you to choose the original Shairport decoder by David Hammerton or the Apple Lossless Audio Codec (ALAC) decoder written by Apple. Shairport Sync must have been compiled with the configuration setting "--with-apple-alac" and the Apple ALAC decoder library must be present for this to work.
 .TP
 \fBinterface=\f1\fI"name"\f1\fB;\f1
-Use this advanced setting if you want to confine Shairport Sync to the named interface. Leave it commented out to get the default bahaviour.
+Use this advanced setting if you want to confine Shairport Sync to the named interface. Leave it commented out to get the default behaviour.
 .TP
 \fBaudio_backend_latency_offset_in_seconds=\f1 \fIoffset_in_seconds\f1\fB;\f1
 Set this \fIoffset_in_seconds\f1 to compensate for a fixed delay in the audio back end. For example, if the output device delays by 100 ms, set this to -0.1.
@@ -225,7 +225,7 @@ Use this setting to specify the format that should be used to send data to the A
 
 "S" means signed; "U" means unsigned; BE means big-endian and LE means little-endian. Except where stated (using *LE or *BE), endianness matches that of the processor. The default is "S16".
 
-If you are using a hardware mixer, the best setting is S16, as audio will pass through Shairport Sync unmodifed except for interpolation. If you are using the software mixer, use 32- or 24-bit, if your device is capable of it, to get the lowest possible levels of dither. 
+If you are using a hardware mixer, the best setting is S16, as audio will pass through Shairport Sync unmodified except for interpolation. If you are using the software mixer, use 32- or 24-bit, if your device is capable of it, to get the lowest possible levels of dither. 
 .TP
 \fBdisable_synchronization=\f1\fI"no"\f1\fB;\f1
 This is an advanced setting and is for debugging only. Set to \fI"yes"\f1 to disable synchronization. Default is \fI"no"\f1. If you use it to disable synchronisation, then sooner or later you'll experience audio glitches due to audio buffer overflow or underflow. 

man/shairport-sync.7.xml

@@ -111,7 +111,7 @@
 	  i.e. the System Configuration Directory.)</p>
 	  
 	  
-	  <p>Within the configuraton file, settings are organised into <i>groups</i>, for 
+	  <p>Within the configuration file, settings are organised into <i>groups</i>, for
 	  example, there is a "general" group of
 	  standard settings, and there is an "alsa" group with settings that pertain to the ALSA
 	  back end. Here is an example of a typical configuration file:</p>
@@ -223,7 +223,7 @@
 
     <option>
     <p><opt>udp_port_range=</opt><arg>range</arg><opt>;</opt></p>
-    <optdesc><p>Use this in conjunction with the prevous setting to specify the 
+    <optdesc><p>Use this in conjunction with the previous setting to specify the
     <arg>range</arg> of ports that can be checked for availability. Only three ports are 
     needed.
     The default is 100, thus 100 ports will be checked from port 6001 upwards until three 
@@ -364,7 +364,7 @@
     <option>
     <p><opt>interface=</opt><arg>"name"</arg><opt>;</opt></p>
     <optdesc><p>Use this advanced setting if you want to confine Shairport Sync to the 
-    named interface. Leave it commented out to get the default bahaviour.</p></optdesc>
+    named interface. Leave it commented out to get the default behaviour.</p></optdesc>
     </option>
     
     <option>
@@ -583,7 +583,7 @@
     specify.</p><p>"S" means signed; "U" means unsigned; BE means big-endian and LE means 
     little-endian. Except where stated (using *LE or *BE), endianness matches that of the 
     processor. The default is "S16".</p><p>If you are using a hardware mixer, the best 
-    setting is S16, as audio will pass through Shairport Sync unmodifed except for 
+    setting is S16, as audio will pass through Shairport Sync unmodified except for
     interpolation. If you are using the software mixer, use 32- or 24-bit, if your device 
     is capable of it, to get the lowest possible levels of dither.
     </p></optdesc>