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

CAR INSTALL.md

@@ -19,7 +19,7 @@ In this example, a Raspberry Pi Zero W and a Pimoroni PHAT DAC are used. This co
 ### Prepare the initial SD Image
 * Download the latest version of Raspbian Lite -- Stretch Lite of 2018-03-13 at the time of writing -- and install it onto an SD Card.
 * Mount the card on a Linux machine. Two drives should appear -- a `boot` drive and a `rootfs` drive. Both of these need a little modification.
-* Enable SSH service by creating a file called `ssh` on the `boot` drive. To do this, mount the drive and CD to its `boot` partiton (since my username is `mike`, the drive is at `/media/mike/boot`):
+* Enable SSH service by creating a file called `ssh` on the `boot` drive. To do this, mount the drive and CD to its `boot` partition (since my username is `mike`, the drive is at `/media/mike/boot`):
 ```
 $ touch ssh
 ```

INSTALL.md

@@ -2,7 +2,7 @@ Simple Installation Instructions
 ==
 Here are simple instructions for building and installing Shairport Sync on a Raspberry Pi B, 2B, 3B or 3B+. It is assumed that the Pi is running Raspbian Stretch Lite – a GUI isn't needed, since Shairport Sync runs as a daemon program. For a more thorough treatment, please go to the [README.md](https://github.com/mikebrady/shairport-sync/blob/master/README.md#building-and-installing) page.
 
-In the commands below, note the convention that a `#` prompt means you are in superuser mode and a `$` prompt means you are in a regular non-priviliged user mode. You can use `sudo` *("SUperuser DO")* to temporarily promote yourself from user to superuser, if permitted. For example, if you want to execute `apt-get update` in superuser mode and you are in user mode, enter `sudo apt-get update`.
+In the commands below, note the convention that a `#` prompt means you are in superuser mode and a `$` prompt means you are in a regular unprivileged user mode. You can use `sudo` *("SUperuser DO")* to temporarily promote yourself from user to superuser, if permitted. For example, if you want to execute `apt-get update` in superuser mode and you are in user mode, enter `sudo apt-get update`.
 
 ### Configure and Update
 Do the usual update and upgrade:

README-DEVELOPMENT.md

@@ -81,7 +81,7 @@ Please refer to the relevant pages for building for the above systems.
 
 **Determine The Configuration Needed**
 
-Shairport Sync has a number of different "backends" that connnect it to the system's audio handling infrastructure. Most recent Linux distributions that have a GUI – including Ubuntu, Debian and others – use PulseAudio to handle sound. In such cases, it is inadvisable to attempt to disable or remove PulseAudio. Thus, if your system uses PulseAudio, you should build Shairport Sync with the PulseAudio backend. You can check to see if PulseAudio is running by opening a Terminal window and entering the command `$ pactl info`. Here is an example of what you'll get if PulseAudio is installed, though the exact details may vary:
+Shairport Sync has a number of different "backends" that connect it to the system's audio handling infrastructure. Most recent Linux distributions that have a GUI – including Ubuntu, Debian and others – use PulseAudio to handle sound. In such cases, it is inadvisable to attempt to disable or remove PulseAudio. Thus, if your system uses PulseAudio, you should build Shairport Sync with the PulseAudio backend. You can check to see if PulseAudio is running by opening a Terminal window and entering the command `$ pactl info`. Here is an example of what you'll get if PulseAudio is installed, though the exact details may vary:
 ```
 $ pactl info
 Server String: unix:/run/user/1000/pulse/native

README.md

@@ -97,7 +97,7 @@ You should also remove the initialisation script files `/etc/systemd/system/shai
 
 **Determine The Configuration Needed**
 
-Shairport Sync has a number of different "backends" that connnect it to the system's audio handling infrastructure. Most recent Linux distributions that have a GUI – including Ubuntu, Debian and others – use PulseAudio to handle sound. In such cases, it is inadvisable to attempt to disable or remove PulseAudio. Thus, if your system uses PulseAudio, you should build Shairport Sync with the PulseAudio backend. You can check to see if PulseAudio is running by opening a Terminal window and entering the command `$ pactl info`. Here is an example of what you'll get if PulseAudio is installed, though the exact details may vary:
+Shairport Sync has a number of different "backends" that connect it to the system's audio handling infrastructure. Most recent Linux distributions that have a GUI – including Ubuntu, Debian and others – use PulseAudio to handle sound. In such cases, it is inadvisable to attempt to disable or remove PulseAudio. Thus, if your system uses PulseAudio, you should build Shairport Sync with the PulseAudio backend. You can check to see if PulseAudio is running by opening a Terminal window and entering the command `$ pactl info`. Here is an example of what you'll get if PulseAudio is installed, though the exact details may vary:
 ```
 $ pactl info
 Server String: unix:/run/user/1000/pulse/native
@@ -609,7 +609,7 @@ This will be followed by the statistics themselves at regular intervals, for exa
 
 "Output frames per second" is the actual rate at which frames of audio are taken by the output device. On a system with a well-conditioned `ntp`-based clock (and without output underruns) this figure should be very accurate after playing material continuously for a period.
 
-"Source clock drift in ppm" is an estimate of the difference in timekeeping between the audio source and the Shairport Sync devive. It is calculated from a linear regression of drift sample data. The number of samples the estimate is based on is given in the next column, "Source clock drift sample count".
+"Source clock drift in ppm" is an estimate of the difference in timekeeping between the audio source and the Shairport Sync device. It is calculated from a linear regression of drift sample data. The number of samples the estimate is based on is given in the next column, "Source clock drift sample count".
 
 "Rough calculated correction in ppm" is a very crude estimate of the amount of interpolation that needs to applied, on average, to keep sync. It is not really to be relied on at this time.