ImGuiTextBuffer: Fix size() to allow using ImGuiTextBuffer with resize(0) patterns.

Removed io.DisplayVisibleMin/DisplayVisibleMax (which were marked obsolete and removed from viewport/docking branch already).

Merged from Docking branch: Various small changes, comments, typos fixes, moved blocks. To reduce overall drift. Should be no-op.

Merged from Docking branch: non-const ImVec2[] operator.

Fixed doc typo (#2326)

Revert "Added PushID(size_t sz) helper (may not be useful/meaningful for non C/C++ languages)." ...

This reverts commit 20bc06a.

Using IM_UNUSED() macro.

Fix various XCode and PVS-Studio static analyzer warnings (#2309)

Added PushID(size_t sz) helper (may not be useful/meaningful for non C/C++ languages).

Internals: Tweaks. Comments about PushID/GetID public function.

ImGuiTextBuffer: Added append() function (unformatted).

Removed trailing spaces (#2038, #2299)

Added checks for "zero-as-null-pointer-constant" warnings for older Clang (#2299, followup to #2277)

FreeType: Minor tweaks previous commit (#2285)

Version 1.68 WIP

Version 1.67

Added a bunch of diagnostic ignore to cope with Clang -Weverything being absurd. Also fixed two legit warnings. (#2277)

Merge branch 'atlas_fixes'

FAQ entry, moved ImTextureId, Gallery links.

ImFontAtlas: Rewrote stb_truetype based builder. ...

- Atlas width is now properly based on total surface rather than glyph count (unless overridden with TexDesiredWidth).
- Fixed atlas builder so missing glyphs won't influence the atlas texture width. (#2233)
- Fixed atlas builder so duplicate glyphs (when merging fonts) won't be included in the rasterized atlas.

ImVector: Added size_in_bytes() helper.

ImFontGlyphRangesBuilder: Using 32-bits fields for storage instead of 8-bit ones, comments, todo.

ImVector: Made reserve() another silly one-liner. It's not longer than other functions and our weird obsessions deserve to be carried with stringent consistence. + Comments

ImVector: Made a struct. Using T/T* in the code instead of value_type/iterator. Renamed index_from_pointer() to index_from_ptr() (was not documented, added in 1.63, users not supposed to use ImVector, hopefully not a big deal).

ImDrawList: Optimized some of the functions for performance of debug builds where non-inline function call cost are non-negligible.

Tabs: Added ImGuiTabBarFlags_NoTooltip flag. (#261, #351) + added helpful assert

Renamed ImFont::GlyphRangesBuilder to ImFontGlyphRangesBuilder. Keep redirection typedef (will obsolete).

Comments/formatting on obsolete stuff

IO: Renamed InputCharacters[], marked internal as was always intended. AddInputCharacter() goes into a queue which can receive as many characters as needed during the frame. This is useful for automation to not have an upper limit on typing speed. Will later transition key/mouse to use the event queue later.

Moved ImVector higher up in imgui :( because we will need it in ImGuiIO.