About: Added build/system info relating to Docking branch.

Merge branch 'viewport' into docking

About: Added build/system info relating to Viewport branch.

Merge branch 'master' into viewport ...

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

About, IO: Added io.BackendPlatformName, io.BackendRendererName for informational/QA purpose.

Added ShowAboutWindow(), About Window now showing various config/build information.

Include <alloca.h> also on macOS (and osxcross) (#2218)

Separator: Fixed Separator() outputting an extraneous empty line when captured into clipboard/text/file.

Merge branch 'viewport' into docking ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Merge misc/shallow changes from Docking branch to minimize drift: moved some blocks, added comments.

Viewport: Fixed a bug where tooltips on their first frame didn't find a monitor leading to the "recovery" code to revert it to the main viewport for a frame. (#1542)

When the focused window become inactive don't restore focus to a window with the ImGuiWindowFlags_NoInputs flag. (#2213)

Comments

Merge branch 'viewport' into docking ...

# Conflicts:
#	imgui_internal.h

Viewport: Avoid calling platform functions when window is not created (apart from Platform_GetWindowDpiScale, documented as such). Main viewport situation is still ambiguous. (#1542)

Viewport: Misc renaming.

Docking: Added io.ConfigDockingTransparentPayload option (to use with ImGuiConfigFlags_ViewportsNoMerge)

Viewport: imgui_impl_sdl2: Added support for PlatformIO Platform_SetWindowAlpha.

Examples: DX12: Fixed compilation of imgui_impl_dx12.cpp in viewport branch. Multi-viewport is still not functional.

Merge branch 'viewport' into docking ...

# Conflicts:
#	imgui.cpp
#	imgui.h

Viewport: Comments.

Merge branch 'master' into viewport

Viewport: Better support for toggling ImGuiConfigFlags_ViewportsEnable. (#2196)

Added ImGuiConfigFlags_None, ImGuiBackendFlags_None for good measure.

Docking: Fixed debug Rebuild operation.

imgui.h: Comments

imgui.h: Moved ImGuiListClipper

mgui.h: Moved ImGuiInputTextCallbackData,, ImGuiSizeCallbackData, ImGuiPayload structures so they are not in the "Helpers" section.

Docking: Maintain CentralNode. When SetNextWindowDockID() on a now split node id, we dig to find the central node or the last focused node. (#2109)

Docking: Comments + maiintain LastFrameFocused per node + using bitfiield for docking bools.