Examples: GLFW: Added mouse cursors support (#1495)

Examples: WIn32: Prefixing every Win32 function calls with :: to denote global namespace in a consistent manner.

Examples: Vulkan: Added support for io.DisplayPos.

Examples: Vulkan: Fixed GLFW calls.

Examples: DirectX10, DirectX11, OpenGL2, OpenGL3: Added support for io.DisplayPos.

Examples: Allegro5, Marmalade: Moved bindings to parent folder. Renamed Allegro stuff from *A5_ to *Allegro5_

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

Examples: DirectX9: Reusing imgui_impl_win32, removed that code from imgui_impl_dx9

Examples: DirectX10: Reusing imgui_impl_win32, removed that code from imgui_impl_dx10

Examples: DirectX11: Extracted imgui_impl_dx11.* instead imgui_impl_dx11 and imgui_impl_win32

Examples: Vulkan: Extracted into imgui_impl_vulkan.*, reused imgui_impl_glfw* files.

Examples: SDL: Extracted into imgui_impl_sdl.*, reused imgui_impl_opengl* files.

Examples: OpenGL2, OpenGL3: Added glPixelStorei() calls borrowed from SDL examples.

Examples: GLFW+GL2: Moved glfw, gl2 files to root folder, split imgui_impl_glfw_gl2 into _opengl2 and reused imgui_impl_glfw

Examples: GLFW+GL3: Split imgui_impl_glfw_gl3 into imgui_impl_glfw and imgui_impl_gl3 (wip)

Examples: GLFW+GL2/GL3: Added glPixelStorei() calls borrowed from SDL examples.

Examples: Renamed .sln file.

Examples: Vulkan: Fix for empty draw data (init time) + fixed warning.

Examples: Vulkan: Added .vcproj files.

Examples: SDL: Fixed minor warning.

Examples: SDL: Added .vcproj files.

Examples: SDL: Minor stylistic tweaks. Fixed handling of ImGuiMouseCursor_None so it doesn't underflow array. Fixed harmless uninitialized pointer. (#1626)

Renamed misleading ImGuiMouseCursor_Move to ImGuiMouseCursor_ResizeAll. SDL: Fixed cursor. (#1626)

Use SDL system cursors in SDL examples. (#1626) ...

(Squashed 4 commits)

Obsoleted the io.RenderDrawListsFn callback, you can call your graphics engine render function after ImGui::Render(). Use ImGui::GetDrawData() to retrieve the ImDrawData* to display..(#1599) ...

Examples: Updated examples.

Examples: Added Changelog to make updates easier.

Examples: SDL: Added Changelog at the top of the imgui_impl files. (#1618)

Added IsAnyMouseDown() helper. ...

Examples: DirectX9/10/11: Using IsAnyMouseDown() instead of local function.

Examples: Vulkan: Fix (something changed in GLFW not including vulkan.h, was unwillingly relying on that)

Merge branch 'context' ...

# Conflicts:
#	examples/allegro5_example/main.cpp
#	examples/directx10_example/main.cpp
#	examples/directx11_example/main.cpp
#	examples/directx9_example/main.cpp
#	examples/marmalade_example/main.cpp
#	examples/opengl2_example/main.cpp
#	examples/opengl3_example/main.cpp
#	examples/sdl_opengl2_example/main.cpp
#	examples/sdl_opengl3_example/main.cpp
#	examples/vulkan_example/main.cpp