Added support for /copy items. Xna project items with no processor or importer specified are imported as copy items.
Whether an item is copied or built can be set by via ContentItem.BuildAction (visible in the property grid).
PipelineProject / ContentItem now hold onto the IController rather than the IView (not totally sure which design makes the most sense).
Added IController / IView callbacks so that the treeview can update a node based on dynamic property values.
Merge branch 'develop' of https://github.com/mono/MonoGame into PipelineTool
Ensure foreground context is current on the main thread

Background must be non-current, otherwise it will raise error 170
(resource is in use) on the next MakeCurrent() call.
Merge pull request #2476 from SickheadGames/PipelineTool

PipelineTool import fixes
Merge pull request #2477 from thefiddler/fix2474

Ensure foreground context is current on the main thread
Fixing SynchronizeWithVerticalRetrace on WindowsGL, it is applied in ApplyChanges instead of immediately (which fails if set in Game constructor)
Remove VSyncEnabled as it is just overwriting what we set from GetSwapInterval. It was only used by the OpenTK Platform.
Merge pull request #2480 from danzel/fix-1862

Make disabling SynchronizeWithVerticalRetrace work on WindowsGL
Fix stencil clear

Some drivers (especially on Android) will obey the stencil test when clearing the stencil buffer (the specs says it shouldn't). This workaround ensure that the stencil buffer will properly be cleared.
Added missing semicolon
Removing assert Pow2 from Texture.GetPitch. It is not appropriate to have this assert in the base Texture.cs file because it is platform specific whether or not this is actually a valid constraint and area already doing their own dimension validation.
Merge branch 'develop' of https://github.com/SickheadGames/MonoGame into develop
Merge pull request #2482 from prollin/patch-1

Fix stencil clear
Now using FreeImage to import Textures on Windows.
Fixed import behavior.
"Compile Include" items are imported as /build items.
"Content Include" items with a CopyToOutputDirectory value other than Never are imported as /copy items.
Added missing Microsoft.Xna.Framework.Graphics exceptions.
Changed SerializableAttribute to DataContract so it can compile on all platforms.
Updated TextureImporter with all of the file types that FreeImage supports.
Feeble attempt at formatting the massive amount of RAW image formats.
Fix for issue #1745
VertexDeclarationReader.cs now enabled for all platforms