Interim work on audio import and processing.
Merge branch 'develop3d' of https://github.com/mono/MonoGame into pipeline
Added content building classes.
Added solution for windows content pipeline.
Added project for the MonoGame Content Builder command line tool.
First pass at parsing the .contentproj and executing the build.
WIP for pipeline.
* Added XML documentation to several classes.
Merge branch 'develop3d' of https://github.com/mono/MonoGame into pipeline
We better handle exceptions in content processing.
PipelineManager expects absolute assembly paths now.
We now use the XNAGSv4 environment variable to resolve XNA assemblies.
We now try to load assemblies from the GAC if possible.
The output folder name is now specified on the command line.
Merge branch 'develop3d' of https://github.com/mono/MonoGame into pipeline
Merge branch 'develop3d' into pipeline
Merge branch 'mgcb' of https://github.com/SickheadGames/MonoGame into pipeline
"Allow unsafe" for all Windows 8 configurations
Some build configurations in the Windows 8 project were missing the "Allow unsafe" option.  This causes a build failure.
Update submodules to point to latest head
Samples and ThirdParty/Libs submodules required updating to latest.
Merge pull request #1189 from slygamer/win8-unsafe

"Allow unsafe" for all Windows 8 configurations
Merge pull request #1190 from slygamer/submodule-update

Update submodules to point to latest head
Fix single sided stencil

When not using TwoSidedStencilMode the same sttings must apply to both
FrontFace and BackFace.

This fixed a transition that creates a stencil mask and happened to be
CounterClockWise. Resualts are now same as XNA.
Merge pull request #1193 from nkast/nkastBranch2

Fix single sided stencil
Merge branch 'develop3d' of https://github.com/mono/MonoGame into pipeline
Fixed a problem for the 3.0 release in linux.