Revert "Merge pull request #346 from playscript/dev-m3-openal"

This merge commit breaks the build when using make, since it uses
PLATFORM_GENERIC to generate the dlls and some methods are missing
on this generic implementation.

This reverts commit 8d7fa47f13c5db5439ffcb7f577b470434646dfe, reversing
changes made to f6aa7175fa4800ca8619b58bb37592220929593d.

Conflicts:
	mcs/class/pscorlib/flash/media/ALAudioPlayer.cs
	mcs/class/pscorlib/flash/media/ios/IOSAudioPlayer.cs
	mcs/class/pscorlib/flash/media/ios/Sound.cs