Merge branch 'viewport' into docking + moved io.ConfigFlags ImGuiConfigFlags_DockingNoSplit to io.ConfigDockingNoSplit ...

# Conflicts:
#	imgui.cpp
#	imgui.h
#	imgui_demo.cpp

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui_demo.cpp

Tests: Adding imgui-test engine hooks (experimental) to provide missing widget state to the testing system.

Tabs: Fixed crash when using TabItem in a regular (non-docking) tab bar. (#2231)

Merge branch 'viewport' into docking ...

# Conflicts:
#	imgui.cpp

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Internals: Nav: Added ImGuiNavLayer_ to clarify semantic of previously integer NavLayer values, and not pretend that increment/decrement operators on them super flexible. + Storage tweaks.

Docking: Added io.ConfigDockingTabBarOnSingleWindows option (mostly made possible by the previous fixes). ...

Note that dock node have regressions compared to current floating window: no collapse, no auto-resize, resize grip under the scrollbar, border issues, general overhead. Will tackle those.

Merge branch 'viewport' into docking ...

# Conflicts:
#	docs/CHANGELOG.txt
#	imgui.cpp

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp

Docking: Another attempt at tidying the inconsistent focus / tab bar reordering issues, and toward generalizing single window dock nodes. (#2109)

Version 1.67 WIP (again, this time IMGUI_VERSION_NUM has leeway for another hot-fix).

Merge branch 'viewport' into docking ...

# Conflicts:
#	docs/CHANGELOG.txt

Merge branch 'master' into viewport ...

# Conflicts:
#	docs/CHANGELOG.txt
#	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_opengl3.cpp
#	examples/imgui_impl_sdl.cpp
#	examples/imgui_impl_vulkan.cpp
#	examples/imgui_impl_win32.cpp
#	imgui.h
#	imgui_demo.cpp

Version 1.66b (will revisit how to change IMGUI_VERSION_NUM across versions, this commit reduces the numerical IMGUI_VERSION_NUM compared to the commit on Nov 22).

Merge branch 'viewport' into docking

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

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

Docking: Added internal DockBuilderGetCentralNode(). Fixed being unable to undock whole node from dock button in DockSpace with a central node. (#2109)

Merge branch 'viewport' into docking ...

# Conflicts:
#	docs/CHANGELOG.txt
#	imgui.cpp
#	imgui_internal.h

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_sdl.cpp

Version 1.67 WIP

Merge branch 'viewport' into docking ...

# Conflicts:
#	docs/CHANGELOG.txt
#	imgui_widgets.cpp

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp

Version 1.66

Merge branch 'viewport' into docking ...

# Conflicts:
#	examples/example_allegro5/main.cpp
#	examples/example_marmalade/main.cpp

Merge branch 'master' into viewport + comments ...

# Conflicts:
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp

Viewport: BeginMainMenuBar(): explicitly set viewport to avoid creating new one when ImGuiConfigFlags_ViewportsNoMerge is set + misc shallow changes.

Viewport: BeginMainMenuBar(): explicitly set viewport to avoid creating new one when ImGuiConfigFlags_ViewportsNoMerge is set + misc shallow changes.

Internals: DragBehavior: Added support for ImGuiDragFlags_Vertical to implement a vertical drag widget (no frontend function provided).