[Android] Split the AboutFragmentItem and InfoFragmentAdapter into their own class files.

It doesn't make sense conceptually to keep them within the AboutActivity, as they are entirely self-contained classes.
Add more sound file extensions to FileMonitor's IsSoundFile.
Merge pull request #149 from lioncash/filemonitor-song-types

Add more sound file extensions to FileMonitor's IsSoundFile.
Merge pull request #145 from lioncash/split-about-activity

[Android] Split the AboutFragmentItem and InfoFragmentAdapter into their own class files.
[Android] Tidy up the dialog buttons that don't do anything.

All we want to do with these is dismiss the dialog. The same can be done by simply passing null.
Merge pull request #154 from lioncash/android-dlg-cleanup

[Android] Tidy up the dialog buttons that don't do anything.
Use correct capitalization for SoundTouch.h in CMakeLists.txt
Fixes Issue 7074:	Typo in CMakeLists.txt
Merge pull request #156 from Parlane/fix_soundtouch

Use correct capitalization for SoundTouch.h in CMakeLists.txt
Fix building on mac without a c/c++ compiler set.
Merge pull request #158 from GUIpsp/master

Fix building on mac without a c/c++ compiler set.