add hand cursor support (+11 squashed commit)

Internals: Settings: Simple optimization caching index into the settings buffer, to remove an unnecessary O(N*M) search during saving. (with N=active root windows during the session, M=stored settings which grows over time)

ImVector: Added index_from_pointer() helper.

Allow menu windows from ignoring the style.WindowMinSize values so short menus are not padded. (#1909)

Double-click on resize grip doesn't need to test HoveredWindow (as button has the flattenchild flag anyway) + double-click on title bar verify that we don't have overlapping items to allow contents in title bar. + Comments

Examples: Apple: Fixed paths of GLFW+GL2 example. (#1906) Update ignore list.

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp

Internals: Various renaming. e.g. NewFrameUpdateHoveredWindowAndCaptureFlags() to UpdateHoveredWindowAndCaptureFlags() + exposed UpdateMovingWindow() in imgui_internal.h.

ArrowButton: Fixed to honor PushButtonRepeat() setting (and internals' ImGuiItemFlags_ButtonRepeat). Setup current line text baseline so that ArrowButton() + SameLine() + Text() are aligned properly.

Internals: Moved some of the SliderBehaviorT code into SliderBehavior to reduce the amount of instanciated code.

Examples: OpenGL3: Remove misleading or unnecessary "#version 150" strings.

Version 1.63 WIP

Demo: Fixed incorrect response to Begin() returning false in overlay demo (which cannot happen since we don't have a title bar, but that doesn't make it a good behaving demo!).

Examples: Fixes.

Fixed merge.

Demo: Fixed mismatched TreePush/TreePop in Property Editor, due to incorrect revert in 826d771 (#1895)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_glfw.cpp
#	examples/imgui_impl_win32.cpp

Examples: Vulkan: nverted the parameters to ImGui_ImplVulkan_RenderDrawData() to be consistent with other bindings.

Version 1.62

Examples: DirectX12: Moved the ID3D12GraphicsCommandList* parameter from ImGui_ImplDX12_NewFrame() to ImGui_ImplDX12_RenderDrawData() which makes a lots more sense. (#301)

Examples: The functions in imgui_impl_xxx.cpp are prefixed with IMGUI_IMPL_API (which defaults to IMGUI_API) to facilitate some uses. (#1888) + Comments in imgui.h

Examples: SDL+OpenGL2: Fixed Makefile. (#1886)

Examples: Fixed bindings to use ImGuiMouseCursor_COUNT instead of old name ImGuiMouseCursor_Count_ so they can compile with IMGUI_DISABLE_OBSOLETE_FUNCTIONS. (#1887)

Readme, Links, Bindings

Fixed warnings + readme

Examples: OSX: Added clipboard support. Fixed ignore list for xcode cruft. Comments about broken keys. (#1873)

Fixed merge.

Viewport: Fix lagging overlay clipping rectangle on viewport owning window (affecting sync of multi-layered docking overlays). This was extremely tricky to find and fix (*). (#1541) ...

(*) Merely assigning viewport->Pos = pos in UpdateMovingWindow() broke a series of thing because the code that assign viewports and viewport flags relied on moving window leaving its own viewport the first time to set the NoInputs flag.

Viewport: Comments. Removed misleading test for !window->ViewportOwned in UpdateSelectWindowViewport(). (#1541)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_opengl2.cpp
#	examples/imgui_impl_opengl2.h
#	examples/imgui_impl_opengl3.cpp
#	examples/imgui_impl_opengl3.h
#	imgui.cpp
#	imgui.h