Merge branch 'develop' of https://github.com/mono/MonoGame into develop
Merge branch 'develop' into InfiniteFlight

Conflicts:
	MonoGame.ContentPipeline/ContentProcessors/MonoGameContentProcessors.csproj
	ThirdParty/Libs
Removed unused non-XNA method Effect.End().
Made the Effect collection classes immutable.
Changed all Effect classes to use arrays to save memory over List<>.
Added EffectParameterCollection.Empty and EffectAnnotationCollection.Empty which saves alot of memory.
Fixes disappearing SoundEffects on iOS (#1123)
This is accomplished by manually setting the buffer properties if the packet does not decode (MonoTouch bug)

Fixed broken sound buffer debug output
Mipmap generation for DXT textures.
Mipmap generation for PVRTC compressed textures.
Fixed crash when changing the value of a processor parameter.
Fixed Dll lookup in MGCB to look in executable path.
Fixed MGFX parser to support +/- numbers in sampler and render state values.
Merge pull request #1645 from SickheadGames/GenerateMipmaps

DXT and PVRTC Mipmap Generation
Merge branch 'develop' into effectopt
Merge pull request #1660 from SickheadGames/effectopt

Effect Memory Optimizations
Fix for Windows Phone 8 template.

Added MediaElement to the WP8 template so now it works.
Protect against the exception if the content list doesn't exist.
Added /quiet switch to MGCB.
Added new target file for compiling a .contentproj in VS using MGCB.
Follow XDG Spec and Application Data on Mac/Linux.
IsNullOrEmpty seems fine.
Merge pull request #1671 from flibitijibibo/savedgamesunix

Follow XDG Spec and Application Data on Mac/Linux.