Comments, FAQ update.

Columns: Fixed destructive small resize. (#1656). The OffsetNorm clamp introduced by #913 was ok as it didn't write back into the storage, which #1499 started doing making it destructive. Right now I don't think the clamp is needed at all. It had uses (eg: hide the issue fixed by bf7481e).

Columns: Extent stop at the right-most clipped pixel. The right-most column might appear a little wider but it's usable space matches the others. (#125). +9 Internal: Store InnerClipRect.

Columns: Clamping MaxX above MinX. This shouldn't have much of a benefit / affect, but the internal values are more sane this way. (#125)

Columns: Adding per-window display in Metrics. Tidying up, removing old code/comments. (#125, #1499, #1656)

Renamed ImGuiStyleVar_Count_ to ImGuiStyleVar_COUNT for consistency with other enums. Added

Added ArrowButton(). Exposed ImGuiDir.

BeginCombo(): Added ImGuiComboFlags_NoArrowButton and ImGuiComboFlags_NoPreview flags + hover color matches drag and sliders.

Merge branch 'patch-1' of https://github.com/stfx/imgui into stfx-patch-1

Combo: Arrow button isn't displayed over frame color, so color is consistent with other button + the button doesn't have inner rounding.

Internal: renamed RenderTriangle() to RenderArrow().

Allow user to override ImTextureId. (#1641)

Makefile: updated sdl_opengl3_example with all changes from #885.

Do not store compiled objects outside the project tree.

Define SOURCES instead of OBJS in Makefiles. ...

OBJS is still deduced from SOURCES, but this change gives better control
over where the object files get actually written.

Use make variables $@ and $^ where appropriate.

Ensure `make clean` is idempotent. ...

Prior to this, `make clean` would fail if the project was not already
fully built, and a second invokation would always fail.

Nav: Added links to PNG/PSD files for PS4 and Switch. Fixed suggested Joy-con mapping as per typical Nintendo-style mapping. (#787)

Internal: Moved IM_NEWLINE helper to imgui_internal.h

Added ImGuiConfigFlags_IsSRGB, ImGuiConfigFlags_IsTouchScreen (strictly for user storage)

Renamed ImGuiNavFlags io.NavFlags to ImGuiConfigFlags io.ConfigFlags. (#787)

README.md typo fix

ImRect: Removed misleading IsFinite() function used by some Nav code.

Compacted some old Breaking Changes notes (Pre July 2015 stuff)

Changelog: Added all change infos since 1.53 up to the current version.

Changelog: Added Changelog with info from 1.48 to 1.53. Haven't added 1.53..current yet.

TreeNode: Renamed Beta ImGuiTreeNodeFlags_NavCloseFromChild to ImGuiTreeNodeFlags_NavLeftJumpsBackHere. (#1079)

ImDrawList: Better looking non-AA rectangle (lower-right corner and rounding). (#1646)

Examples: Fix d749d49 missing the deletion code. (#1217)

Examples: OpenGL3: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context. (#1217)