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

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Viewport: Fix handling of PlatformRequestResize/PlatformRequestPos. when OS decoration are enabled via ImGuiConfigFlags_ViewportsDecoration .

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.

Merge branch 'master' into viewport ...

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

Comments, tweak

Viewport: Minor tweaks, better struct layout.

Viewport: Fixed a viewport bug which led some popups to merge in underlying host viewport when they should be z-over their parent viewport.

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

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).

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

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

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.

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)

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.

Merge branch 'master' into viewport

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

Added ImGuiConfigFlags_None, ImGuiBackendFlags_None for good measure.

Viewport: Merging fixes + relying on multiple viewport overlaps. Follow-up to previous attempts are reworking the split/merge mechanisms. (#1542)

Viewport: Fixes moving child menu viewport (fix 379733a).

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_sdl.cpp

Viewport: Fix viewport regression with protruding child window creating their own viewport. (fixes cae4d02, 760c1d95) (#1542)

Viewport: Added support for minimized window which caused problem when ImGuiBackendFlags_HasMouseHoveredViewport was not supported. (#1542) + todo

Viewport: Avoid unnecessary reapplying platform pos/size every frame. (#2205) + Fix GLFW ImGui_ImplGlfw_CreateWindow() from not applying position immediately. Clear LastNameHash properly (bug already fixed in Docking branch)