Viewport: Popups, Tooltips can individually request no task bar icons to the platform layer. (#1542)

Examples, Platform, Viewport: Fixed inconsistent window ownership issues. Added comments. Made Win32/SDL back-ends track ownership.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/vulkan_example/main.cpp
#	imgui.h

Examples: Added missing calls for ::DestroyWindow, glfwDestroyWindow() + fix old comments.

Fixed erroneous call to io.Fonts->ClearInputData() + ClearTexData() that was left in DX10 example but removed in 1.47 (Nov 2015) in every other back-ends. (fixes 6cee2fc) (#1733, ~#1731) + assert

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx12.cpp
#	examples/imgui_impl_dx9.cpp
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	examples/vulkan_example/imgui_impl_glfw_vulkan.cpp
#	imgui.cpp
#	imgui.h
#	imgui_internal.h

Renamed ImGuiConfigFlags_NoSetMouseCursor to ImGuiConfigFlags_NoMouseCursorChange. Followup to 75c3793 two weeks ago. (#787, #1495, #1202) + comments

Viewport, Platform, Examples: Added support for transparent window via PlatformIO Platform_SetWindowAlpha (#1542) + fixes for GLFW 3.3

Viewport: Comments about honoring ImGuiViewportFlags_NoInputs and MouseHoveredViewport. (#1542)

Viewport: Renamed RenderPlatformWindows() to RenderPlatformWindowsDefault(), tweaked examples and emphasis optional Viewport code path. (#1542)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx12.cpp
#	examples/imgui_impl_dx9.cpp
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.h
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.h
#	imgui.cpp

Examples: Tweak comments. (#1704, #1708).

Examples: Win32: Fixes for MingW which doesn't support a 2007 define? I have no idea why people still use MingW (#1704, #1463)

Examples: SDL: Note about SDL breaking the IME under Windows (I can't seem a way SDL2 Windows IME implementation can possibly work, the functions are never called/referenced).

Examples: GLFW: Don't alter cursor mode if GLFW_CURSOR input mode is GLFW_CURSOR_DISABLED. (#1202) [@PhilCK]

Examples: GLFW: Don't alter cursor mode if GLFW_CURSOR input mode is GLFW_CURSOR_DISABLED. (#1202) [@PhilCK]

Examples: OpenGL2: Added multi-viewport support in the OpenGL2 back-end. (#1542) + Metrics: Fix undisplayed flag.

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx12.cpp
#	examples/imgui_impl_dx9.cpp
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	examples/vulkan_example/imgui_impl_glfw_vulkan.cpp
#	imgui.h

IO: Added ImGuiConfigFlags_NoSetMouseCursors. Added ImGuiBackendFlags_HasMouseCursors, ImGuiBackendFlags_HasSetMousePos. (#787, #1495, #1202)

Added ImGuiBackendFlags for backend to expose its capabilities. Added ImGuiBackendFlags_HasGamepad. (#787, #1542)

IO: Renamed io.WantMoveMouse to io.WantSetMousePos (was added in 1.52, _not_ used by core and only honored by some binding ahead of merging the Nav branch) + internal renaming (#787)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/sdl_opengl2_example/main.cpp
#	examples/sdl_opengl3_example/main.cpp
#	examples/vulkan_example/main.cpp

Examples: Renamed applications to emphasis on use of GLFW as a platform framework + minor local tweaks

Examples: Vulkan: Fix missing subpass dependency ...

Without a dependency between pWaitDstStageMask (COLOR_ATTACHMENT_OUTPUT)
and the render-pass, the UNDEFINED -> COLOR_ATTACHMENT_OPTIMAL transition
might happen before the image is ready to be used.

Examples: Vulkan: Using VK_PRESENT_MODE_MAILBOX_KHR. Disable IMGUI_UNLIMITED_FRAME_RATE by default. Fixed warnings. (#1042)

Viewport, Platform: Added void* to render/swap buffer functions. Comments. (#1542, #1042)

Viewport, Examples: Renamed types used by examples. (#1542)

Viewport, Platform: Refactored platform interface. Removed need to use imgui_internal.h in backends. Split viewport into public facing ImGuiViewport and internal structure. Exposing enough data to provide custom tweaked renderers. Renamed handlers, fixed lots of inconsistencies. (#1542, #1042)

Viewport, Platform: Internal renaming to use more consistent (OsDesktopPos > PlatformPos). (#1542)

Viewport, Platform: SDL: Makes the CreateViewport function restore current GL context so in theory it is free from side-effect. That said, it seems like there is a bug in SDL because our CreateViewport (currently in Render(), not for long) have affect a jerky side-effect if SDL_GL_MakeCurrent() is called before Render(). (#1542)