(fix "Show Debug Log" checkbox in Metrics window)

TabItem: revert support for SetNextItemOpen(true) at it creates too much ambiguity with p_open/close button vs Selected state. (#5262)

Revert a small part of 4b972961.

TabBar: Tweak shrinking policy so that while resizing tabs that don't need shrinking keep their initial width more precisely.

Has been the case before but adding support for SetNextItemWidth() #5262 made this more noticeable.

Sliders: An initial click within the knob/grab doesn't shift its position. (#1946, #5328) + Adjust default GrabMinSize.

Internals: SliderBehaviorT: Minor refactor, clearer 0.0/1.0 early out. Should be no-op from user's point of view.

ScaleValueFromRatioT() had early 0.0/1.0 ratio tests, shifting most of function by one indent.

MovingWindow auto-cancelled if active id is stolen (instead of ill-defined bahavior + assert in docking).

Followup to 27343efb

Nav, Focus: Changed SetKeyboardFocusHere() to not behave if a drag or window moving is in progress + move KeepAliveID() call from Scrollbar() to ScrollbarEx()

Drag, Slider: rework slightly or CTRL+Click or SetKeyboardFocusHere() will show 1 change of active id in the log (rather than a set,clear,set sequence)

Debug: Add more log. Reworked IMGUI_DEBUG_PRINT IMGUI_DEBUG_PRINTF. Added internal IsDragDropActive() helper.

DebugLog() output to TTY by default.
Amend 1d6e34f3.

Amend 076d8fc8. Eventually we should REALLY clean up the SetNavWindow SetNavID SetFocusID FocusWindow fiasco.

Internal: renamed old IMGUI_DEBUG_LOG() to IMGUI_DEBUG_PRINT().
Amended once.

Nav: Fixed issues with nav request being transferred to another window when calling SetKeyboardFocusHere() and simultaneous changing window focus. (#4449)

Menus: Separate menu sets by nav layer. (#3496, #4797) + Demo: Remove incorrect and useless suggestion to use PushID().

Fixes a common case where opening menu in one nav layer and hovering a menu in another nav layer would open that menu without a click.

InputText: Amends and tidying up: Fixed undo/redo state corruption when editing buffer in user callback. (#4947, #4949)

Internals: wrapped used of g.TempBuffer into ImFormatStringToTempBuffer/ImFormatStringToTempBufferV helpers.

This leaves us room for growing the buffer if needed, and gives us a resizable buffer available for other work.

InputText: Fixed an undo-state corruption issue when editing buffer before reactivating item. (#4947) + Metrics: Added "InputText" section.

Amend 83d22f4e

InputText: Fixed a one-frame display glitch where pressing Escape to revert after a deletion would lead to small garbage being displayed for one frame. (#3008)

Curiously very old, amend 83efdcec and bdbb2b21. Using stb_ functions updated ->CurLenA without updating ->TextA, leading to `buf_display_end = buf_display + state->CurLenA;` in the display.
Since f3ab5e62 they are 1 case out of 4 which didn't apply back to ->TextA and this is essentially the one where we ensure appliance. Another solution would be to alter the lower display code, but applying to TextA makes things more consistent.

Docs: Update templates with link to Contributing guidelines. Add numerical version number in demo. Moved. (#5337)

Copied from issue #2261 with small rework + added "Copyright / Contributor License Agreement"

Backends: OpenGL: Partially revert 1.86 change of using glBufferSubData(): now only done on Intel GPUs. (#4468, #3381, #2981, #4825, #4832, #5127)

Essentially reverts 389982eb for non-Intel GPUs + update imgui_impl_opengl3_loader.h
Amended once (force-pushed).

Renamed CaptureMouseFromApp() and CaptureKeyboardFromApp() to SetNextFrameWantCaptureMouse() and SetNextFrameWantCaptureKeyboard(). Added demo. (#5304, #4831, #4480, #533)

Backends: OpenGL3: Fix state corruption on OpenGL ES 2.0 due to not preserving GL_ELEMENT_ARRAY_BUFFER_BINDING and vertex attribute states. (amends)