window: Move to GitHub.

Conflicts:
	LICENSE
	README.md
gl2: Move to GitHub.

Conflicts:
	LICENSE
	README.md
	doc.go
	state.go
gl2: Fix resize package path.
gl2: Fix references to math package.
gl2: Make vet happy.

Conflicts:
	state.go
internal/resize: Move resize package here.
gl2: Implement NativeTexture.ChosenFormat; see azul3d/gfx#5
gl2: Incorporate changes to the gfx.Renderer interface.

See azul3d/gfx-gl2#2 for more information.
gl2: Fix comment typos.
gl2: At least return nil if render to texture is not supported.

See azul3d/gfx-gl2#2
gl2: Render to texture mostly working. Fix mipmapping.

For mipmapping see azul3d/gfx-gl2#5
For RTT see azul3d/gfx-gl2#2

Conflicts:
	doc.go
	rtt.go
gl2: Implement resource cleanup for RTT.

See azul3d/gfx-gl2#2

Conflicts:
	rtt.go
gl2: Fix RTT canvas Download. Fixes azul3d/gfx-gl2#2

Conflicts:
	rtt.go
gl2: go fmt

Conflicts:
	rtt.go
gl2: Support custom per-vertex attributes. Fixes azul3d/gfx-gl2#8
gl2: Mark TexCoordSet's as not changed after updating VBO's. Fixes azul3d/gfx-gl2#10
gl2: Add support for gfx.Vec4 shader inputs. Fixes azul3d/gfx-gl2#9
gl2: Sort imports via goimports.

Conflicts:
	rtt.go
	state.go
window: Sort imports via goimports.
gl2: Implement implicit obj.Bounds call; Fixes issue azul3d/gfx-gl2#8