Introduced skeleton classes: BillboardText3D, BillboardTextModel3D
Introduced a new "BillboardVertex" data type
Added initial implementation of BillboardTextModel3D, BillboardText3D
Introduced "RenderBillboard" render technique
Undo changes in HelixToolkit.Wpf.SharpDX_NET40.sln
Merge pull request #1 from Benglin/master

Initial implementation of billboard text support
More BillboardText3D implementation.
Add bitmap font loading in BillboardText3D constructor.
Merged "TEXCOORD" and "OFFSET" into just one "TEXCOORD" field
Implemented the new "BillboardText.fx"
Removed unwanted fields in classes to avoid compilation warnings
Merge branch 'master' of https://github.com/DynamoDS/helix-toolkit into ianMaster

Conflicts:
	Source/HelixToolkit.Wpf.SharpDX/Model/Elements3D/BillboardTextModel3D.cs
Merge pull request #2 from Benglin/master

Implemented shaders for billboard text
Added "vViewport" variable to "BillboardTextModel3D"
Merge pull request #3 from Benglin/master

Added "vViewport" variable to "BillboardTextModel3D"
Added texture support for "BillboardTextModel3D"
Merge pull request #4 from Benglin/master

Added texture support for "BillboardTextModel3D"
Update shader name. Init collections.
Updated billboard pixel shader to deal with alpha channel
Merge branch 'master' of https://github.com/DynamoDS/helix-toolkit into ianMaster

Conflicts:
	Source/HelixToolkit.Wpf.SharpDX/Resources/_default.bfx