Restore SLN which in Docking branch includes more projects.

Merge branch 'master' into docking ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx9.cpp
#	examples/imgui_impl_opengl3.cpp
#	imgui.h
#	imgui_demo.cpp

Examples: Fixed example vcproj names in Viewport branch.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_sdl.cpp

Examples: Renamed example folders. (#1870)

Examples: Added .. folder in include path to remove the awkward #include "../imgui_impl_xxx.h" statements.

Examples: DirectX12: Removed from current solution which is meant to be VS2010 compatible for now (will change soon).

Merge branch 'jdm3_master'

Examples: Added SDL+Vulkan example, the abstraction worked here :) (ref #1367)

Examples: Added SDL, Vulkan examples to .sln file.

Examples: Renamed .sln file.