MonoGame.Framework GUIDs reverted to previous state with the exception of:

Angle, new GUID generated as it was using the same as the Windows platform
WindowsPhone, new GUID generated as it was using the same as the Windows platform

Fix requested as part of #2560
Replaced GUID's in MonoGame.Framework.Net.definition
Modified as per @tomspillman request
Updated WindowsGL GUID
Several fixes/improvements to XACT.
Create tools.md
Create 2mgfx.md
Update tools.md
Create mgcb.md
Update mgcb.md
Added tool docs.
Update 2mgfx.md
Update 2mgfx.md
Update 2mgfx.md
Merge pull request #2563 from SickheadGames/XACT_Fixes

Several fixes/improvements to XACT and SoundEngine behavior.
Merge pull request #2561 from DDReaper/develop_ProjectGuidRevert

MonoGame.Framework GUIDs reverted to previous state as per #2560 request
Added PS4 note.
Merge pull request #2564 from SickheadGames/doc2

2MGFX and MGCB Docs
Renamed ShaderInfo.fileName to FilePath.
Renamed ShaderInfo.fileContent to FileContent.
Added ShaderInfo.OutputFilePath.
Added ShaderInfo.AdditionalOutputFiles for registering any additional files that need to be cleaned on content rebuilding.