Internals: ButtonBehavior(), IsHovered() moved the responsability of flatten_child higher level to ButtonBehavior() - not super sure about the elegance of this

IsItemHovered(), ItemAdd(): finishing cleaning up, moved the code to IsItemHovered() so ItemAdd() is more lightweight and the two IsXXXHovered functions are now very similar, making their differences less confusing.

ItemAdd(), not performing computation for IsItemRectHovered() which does them itself, allowing us in the next commit to optimize ItemAdd() and make its logic more consistent with IsHovered().

Removed extraneous ImGui:: prefixes. Declared ColorEditOptionsPopup in imgui_internals.h. Tweaked internal signatures.

ImFontAtlas: Refactored internals API to 1) avoid building lookup table multiple times for merged fonts + 2) allow the mapping of custom icons inside fonts (wip, uncommited)

Separator(): output vertical separator when used in horizontal layout mode, so it works in menu bars.

Exposed PushMultiItemsWidths() to imgui_internal.h

BeginCombo(): rework internals a little to make it easier to provide custom combo-like elements relying in BeginCombo(). ...

BeginPopupEx() doesn't enforce AlwaysAutoResize flag anymore.

SetNextWindowPos: added a ImVec2 pivot parameter for positioning a given a center, bottom-right position, etc. As a generalization of SetNextWindowPosCenter() which is now obsolete. This will be useful for combo-like popups as well. ...

Demo: Simple-overlay window uses the SetWindowPos pivot to select a corner to position itself at.

Popups: Exposing a little more of popups internals in imgui_internals.h

Remove commas after last item in enumeration. ...

This brings these enums to match the rest of the code and fixes
2 warnings under clang about using C++11 extensions.

Internals: ImGuiItemFlags comments

Internals: moved ButtonRepeat and AllowKeyboardFocus bools/stacks to a generic ItemFlags stack. Merged from Navigation branch.

Fixed WantTextInput from being true when an activated Drag or Slider was previously turned into an InputText(). (#1317)

Minor comments + renaming internal fields

Combo: Internally split into BeginCombo(), EndCombo(), toward a more flexible combo api.

Added IsWindowAppearing().

Merged from Navigation branch. TAB/Alt-TAB processing now deactivate if holding Ctrl.

Added GetKeyPressedAmount() (from Nav branch) to be able to measure fast repeat rate accurately. Added internal CalcTypematicPressedRepeatAmount() function.

Merge various minor things (supposedly harmless) from Navigation branch into Master to reduce differences. (#787)

Added overcomplicated RenderRectFilledRangeH() to fix rounded progress bar, which will also help for range widgets and perhaps sliders grabs over rounded areas. (#1296, #76)

ImSwap() helper.

Internals: Renamed some ImGuiCorner enums.

Internals: Split some code out of NewFrame() into an Initialize() function.

ImFontConfig: Added RasterizerMultiply option to alter the brightness of individual fonts at rasterization time, which may help increasing readability for some. Added RasterizerFlags for custom rasterizer flags (aka imgui_freetype)

Marked all fmt + va_list functions with format attribute so GCC/Clang can warn about them. Not ignoring -Wsuggest-attribute=format anymore for GCC/Clang.

Version 1.52 WIP

Version 1.51

(internals) Renamed FocusedWindow to NavWindow to match terminology of navigation branch

Merge 20a0fde Tidying up default clipboard handler for non Windows-OS (from Nav branch)