Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx10.h
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_glfw.h
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl2.h
#	examples/imgui_impl_opengl3.cpp
#	examples/imgui_impl_sdl.cpp
#	examples/imgui_impl_sdl.h
#	examples/imgui_impl_vulkan.h
#	examples/imgui_impl_win32.cpp

Examples: FreeGLUT: Fixed mapping of Space key. (#801)

Comments, documentation

Examples: FreeGLUT: Added FreeGLUT bindings. Added FreeGLUT+OpenGL2 example. (#801)

Examples: Win32: Fixed handling of mouse wheel messages to support finer position messages (typically sent by track-pads). (#1874)

Examples: Comments to make ImGuiConfigFlags_NoMouseCursorChange more visible (#1027). + Allegro5: Added support for ImGuiConfigFlags_NoMouseCursorChange flag.

Fixed Travis path + various paths in comments/documentations

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_sdl.cpp

Examples: Renamed imgui_impl_sdl2.cpp to imgui_impl_sdl.cpp (#1870) + changelog bits

Examples: Renamed example folders. (#1870)

Merge branch 'examples_refactor2' into viewport (#1870) ...

# Conflicts:
#	examples/README.txt
#	examples/directx11_example/main.cpp
#	examples/directx12_example/main.cpp
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx12.cpp
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl2.h
#	examples/imgui_impl_opengl3.cpp
#	examples/imgui_impl_sdl2.cpp
#	examples/imgui_impl_sdl2.h
#	examples/imgui_impl_vulkan.cpp
#	examples/imgui_impl_vulkan.h
#	examples/imgui_impl_win32.cpp
#	examples/imgui_impl_win32.h
#	examples/opengl2_example/main.cpp
#	examples/opengl3_example/main.cpp
#	examples/sdl_opengl2_example/main.cpp
#	examples/sdl_opengl3_example/main.cpp
#	examples/sdl_vulkan_example/main.cpp
#	examples/vulkan_example/main.cpp
#	imgui.cpp
#	imgui.h

Big example binding refactor (manually imported from Viewport branch, stripped out of Viewport code). (#1870) ...

Read examples/README.txt for some details.
ImDrawData: Added DisplayPos, DisplaySize fields honored by all backends (not strictly necessary to honor just now, but doing it to be ahead)

Examples: Documentation

Examples: Fixed Makefile, batch files.

Examples, Platform: Removed the call to ImGui::NewFrame() from the platform _NewFrame() function e.g. ImGui_ImplWin32_NewFrame(), ImGui_ImplSDL2_NewFrame(), ImGui_ImplGlfw_NewFrame(), etc. Moved to main.cpp for consistency. (#1542)

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

Missing examples changelog bits and todo list

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.h
#	examples/vulkan_example/imgui_impl_glfw_vulkan.cpp

Examples: OpenGL3: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state. (#1836)

Examples: iOS: Fixed missing call to CreateContext() + various shallow coding style tweaks. (#1835)

Examples: Comments about GLSL version not being the same as GL context version. (#1828)

Examples: GLFW: Made it possible to Shutdown/Init the backend again (by reseting the time storage properly). Changelog. Added to Vulkan example. (#1827)

Examples: GLFW* Make subsequent window creation possible.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	imgui.cpp
#	imgui.h

Examples: OpenGL3: Trying to make the call to glBindSampler optional to make the example code easier to use/share with different context version. (#1806)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	imgui.cpp
#	imgui.h

Viewport, Platform: Cleaned up xxx_UpdateMouseCursor() functions to make them more consistent. (#1542)

Viewport, Platform: Win32: Fixed handling of io.WantSetMousePos + added a bunch of comments. GLFW, SDL2: Added handling of io.WantSetMousePos. (#1542)

Viewport: Changed Monitor field to use Pos+Size (more consistent), changed FullMin,FullMax to MainPos,MainSize. Made main viewport accessible in PlatformIO on first frame. Fixed casing of ImGuiViewportFlags_TopMost flag. (#1542)

TODO list update + Changelog and comments for #1803.