Synced/merged minor cruft from docking branch to minimize drift. AFAIK the only meaningful no-op change is that the call UpdateHoveredWindowAndCaptureFlags() was moved above UpdateMouseMovingNewFrame() to match what docking branch has been doing for a while.

Comments about obsoleted features version. Todo. Clarify tab bar initial offset (useful if we decide to remove the half-windowpadding clip margin).

Comments, todo entries, moved ImGuiSelectableFlagsPrivate in higher ranges to match others.

Fixed InputFloatX, SliderFloatX, DragFloatX functions erroneously reporting IsItemEdited() multiple times when the text input doesn't match the formatted output value (e.g. input "1" shows "1.000"). It wasn't much of a problem because we typically use the return value instead of IsItemEdited() here. (#1875, #2034)

Internal: Renamed fields + minor tweaks (probably shallow break stack-layout pr, sorry!)

Internal: Refactored Separator into SeparatorEx(), exposed ImGuiSeparatorFlags_SpanAllColumns in imgui_internal.h and support without. (#759) + misc comments

Version 1.70

Drag and Drop: Fixed drag source with ImGuiDragDropFlags_SourceAllowNullID and null ID from receiving click regardless of being covered by another window (it didn't honor correct hovering rules). (#2521)

Popups: Closing a popup restores the focused/nav window in place at the time of the popup opening, instead of restoring the window that was in the window stack at the time of the OpenPopup call. (#2517) ...

Among other things, this allows opening a popup while no window are focused, and pressing Escape to clear the focus again.

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

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

Clarified asserts comments + todo entries. (#2500)

Examples: Emscripten: Switched to WebGL1/ES2, Added Changelog, Updated links, Added ignore list, Fixed warning with older versions. Removed reliance on C++11 (would warn on some compiler). Improved html template, removed undesirable options, reduced log size. Tweaked main.cpp. (#2494)

Internals: Tweak ItemSize calls. Added todo items.

InputText: Made Shift+Tab consistently do nothing regardless of whether the back-end emits both char and keys or just keys. (#2467, #1336)

InputText, Examples/SDL: Emulate \t input if back-end doesn't provide it. (#1336, #2467) ...

+ Fix some output filename in SDL build batch files.

InputText: Work-around for buggy standard libraries where isprint('\t') returns true. (#2467, #1336) ...

Not using isprint. + todo items.

Comments (#2441) + Freeglut fixes (#2430)

Comments, todo list, remove trailing spaces.

Version 1.69, comments, typos

Fix typos. (#2413)

Internal: Text: Extracted TextUnformatted into TextEx over which we can freely atter the signature. Clarified current large text behavior of TextUnformatted with explicit ImGuiTextFlags_NoWidthForLargeClippedText flag (always set).

Text: Fixed large Text/TextUnformatted call not declaring its size when starting below the lower point of the current clipping rectangle. Somehow this bug has been there since v1.0! It was hardly noticeable but would affect the scrolling range, which in turn would affect some scrolling request functions when called during the opening frame of a window.

Log/Capture: Fixed LogXXX functions 'auto_open_depth' parameter being treated as an absolute tree depth instead of a relative one. Fixed CollapsingHeader trailing ascii representation being "#" instead of "##". Minor tidying up the of code.

InputText: Renamed some local variables to clarify code. Should be a no-op functionality wise. TODO items.

Menus: Tweaked horizontal overlap between parent and child menu (to help convey relative depth) from using style.ItemSpacing.x to style.ItemInnerSpacing.x, the later being expected to be smaller. (#1086)

Removed trailing spaces from text files. (#2038, #2299)

ImDrawList: Fixed AddCircle(), AddCircleFilled() angle step being off, which was visible when drawing a "circle" with a small number of segments (e.g. an hexagon). (#2287) [@baktery] ...

+ Demo tweaks

TODO update + internals: changed order or ImGuiLayoutType enums to allow using them for indexing.

Merge branch 'atlas_fixes'