Change .gitignore to track *.cfg files in /res/keyboard/
Added de_CH.kbd.cfg and fr_CH.kbd.cfg keyboard mapping files. Thanks to Markus Baertschi. Fixes https://bugs.launchpad.net/mixxx/+bug/1401838
Deere skin: Add simple button styles for hover and pressed state.
LateNight: Try to make previewdeck remember its openc/closed state

still not working??
Upgrade from SoundTouch 1.6.0 to 1.8.0.

Fixes a portability-related segfault on Windows x64 reported in
Bug #1402219.
Call SoundSource::setChannels in SoundSourceOggVorbis and SoundSourceSndFile. Fixes Bug #1402262.
Add unit test that we can open AIFF, FLAC, MP3, Ogg, and WAV files using
the pre-existing cover-art test files.
Delete obsolete include directives
New SoundSource/AudioSource API

This is the first step towards a better/cleaner SoundSource API.
The operations for reading audio data have been moved into the
new abstract base class AudioSource.

Currently SoundSource inherits from AudioSource for technical reasons.
This is too much much coupling that needs to be broken up. I have
already some ideas on how to resolve it, but first this work needs to
be integrated.

During the refactoring I've noticed, that the quality and maturity of the
audio decoders for different file types greatly varies:

Good/mature:
- FLAC
- Ogg
- Opus
- WavPack
- libsndfile

Mediocre:
- MP3

Ugly/inefficient:
- M4A
- ModPlug

Untested AudioSource API:
- Apple CoreAudio
- Windows Media Foundation

Unfinished AudioSource API (just a hack):
- FFmpeg

Especially the code for the M4A decoder should be revised and cleaned up as
soon as possible, followed by a review of the MP3 decoder. Reading audio
data must work as stable and efficient as possible. This has priority over
the improvement of the internal software architecture!
Rewrite of the M4A decoder without legacy code
Slightly simplify the analysis of tracks
Initial cleanup of SoundSourceMp3 code
More SoundSourceMp3 optimizations and improvements
Minor cleanup
Fix unit tests after rebasing