Internals: Added DataTypeApplyOp, DataTypeApplyOpFromText to imgui_internal.h

Fix 61d9258 when there is not scrollbar "Window: Fixed contents region being off by WindowBorderSize amount on the right when scrollbar is active."

Internals: Renaming. Renamed ImGuiPopupRef to ImGuiPopupData for consistency and added constructor.

Internals: Exposed ImGuiDataTypeInfo, DataTypeGetInfo(), DataTypeFormatString(). Comments.

Internals: Begin: Moved OuterRectClipped/InnerMainRect/InnerClipRect computation higher up in the function, next to ContentsRect/WorkRect code. Removed commented out debug drawing code which is now available in Metrics window.

Window: Fixed contents region being off by WindowBorderSize amount on the right when scrollbar is active.

Internals: Nav scrolling uses InnerMainRect instead of InnerClipRect.

Separator: Declare its thickness (1.0f) to the layout, making items around separator more symmetrical.

Nav: Fixed Drag/Slider functions going into text input mode when keyboard CTRL is held while pressing NavActivate.

Internals: TempInputText: Tidying up DragScalar / SliderScalar / TempInputTextScalar.

Internals: TempInputText: Rename InputScalarAsWidgetReplacement() -> TempInputTextScalar(), ScalarAsInputTextId -> TempInputTextId, small tidying up in affected functions.

Internals: Using more explicit PushOverrideID() helper + renamed equivalent internal tree helper.

Examples: Glut: Added note about missing cursor support. (#2375, #2465)

Window: Fixed window with the AlwaysAutoResize flag unnecessarily extending their hovering boundaries by a few pixels (this is used to facilitate resizing from borders when available for a given window). One of the noticeable minor side effect was that navigating menus would have had a tendency to disable highlight from parent menu items earlier than necessary while approaching the child menu. ...

+ Changelog fixed unfinished sentence and tweaks,

MenuItem, BeginMenu: Fix undesirable tall frames in horizontal layout context, which would be visible when trying to use rounded selectable/menus. ...

PushStyleVar: Added comments in the assert message.
Minor tweaks.

Misc comments, internal renaming, added disable indentation option to Columns demo section.

Examples: SDL: Gamepad support minor amend. Fixes ImGuiBackendFlags_HasGamepad not being set. Enable in Emscripten demo. Tweaks. (#2509, #2484).

Added support to use controllers via SDL_GameController. (#2509) ...

Updated sdl examples to use SDL_INIT_GAMECONTROLLER flag

Increased IMGUI_VERSION_NUM arbitrarily, help narrowing down reports that don't include a commit hash. Add comments.

Examples: SDL: Removed unused code. (#2484)

Internals: ImHashStr() default parameter.

Added SetNextItemWidth() helper to avoid using PushItemWidth/PopItemWidth() for single items.

Demo: Documents: Fix misusage of ListBoxHeader().

Misc: Fixed PushItemWidth(-width) (for right-side alignment) laying out certain items (button, listbox, etc.) with negative sizes if the 'width' argument was smaller than the available width at the time of item submission,

Internals: Rework CalcItemWidth / CalcItemSize but make their similarities and their differences more obvious. (#2449)

Added commentary about ContentRegion functions. Added internal GetContentRegionMaxScreen() to facilitate internal code at the moment.

Internals: Moved CalcItemSize next to CalcItemWidth, added comments to clarify their respective intent. Should have no side effect.

Combo, Slider: Improve rendering in situation when there's there's very little space available.

Internals: Columns: Tweaks, renaming. Metrics: Show rectangles for child windows. ...

Renamed SameLine() first parameter.

Columns: Fixed boundary of clipping being off by 1 pixel within the left column.