Nav: Track nav input source more generally (gamepad vs keyboard) (#787) + update todos and demo tweaks

Style: CloseButton() now display a proper cross. Using Button colors for background. Removed ImGuiCol_CloseButton, ImGuiCol_CloseButtonActive, ImGuiCol_CloseButtonHovered as the closing cross uses regular button colors now. (#707)

Internals: Columns renaming fields

Updated Changelog following merge of #1619 + fixed entry added to wrong version Changelog in 1ef1acb

Merge branch 'master' into font_offset

Comments, Changelog

Render: Removed the code that disable render if style.Alpha is 0.0f, it is both incorrect (as style Alpha can be modified mid-frame), not really necessary (just tested that full Alpha = 0 will lead to empty draw lists!) and misleading (bulk of the work was already done).

Fixed type cast warning.

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().

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

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

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.

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

Merge branch 'master' of https://github.com/podgorskiy/imgui into podgorskiy-master

A tiny optimization to ImLineClosestPoint. Removed unnecessary sqrtf call. ...

ab_lenSqr -> ab_len_sqr
Moved line where ab_len_sqr is computed after the first return

Nav: Internals: Exposed NavMoveRequestCancel in imgui_internal.h (#1640)

Drag and Drop: BeginDragDropSource(): temporarily removed the optional mouse_button=0 parameter because it is really usable in typical conditions at the moment. (#143, #1637)