add shortcut+backspace support

osx uses super+arrows for home/end, built on work in ocornut/imgui#473

Using GetCurrentWindowRead() instead of GetCurrentWindow()

SetCursorScreenPos() fixed not adjusting CursorMaxPos as well

ImGuiListClipper: Fix to behave within column (#661, #662, #716)

ImGuiListClipper: fixed automatic-height calc path dumbly having user display element 0 twice (#661, #716) ...

First bug out of two. Was easily visible using e.g. 50% alpha text.

NextColumn() tidying up with a sane early out

Added assert to track stb_textedit.h issue (#715)

InputTextMultiline(): Fixed Ctrl+DownArrow moving scrolling out of bounds

Fixed Windows default clipboard leaving its buffer unfreed on application's exit. (#714)

Minor bits

Comments amend 3c8e490 (committed before saving last comment edit) (#703)

Comment on dealing with io.WantCaptureKeyboard (#703)

InputText: render currently edited buffer from the internal buffer, toward #701

InputText, ImGuiTextFilter: using strncpy instead of printf("%s").

Wrapped text: fixed incorrect testing for negative wrap coordinates, they are perfectly legal. (#706)

ColorEdit4(): better preserve inputting value out of 0..255 range, display then clamped in Hexadecimal form

Fixed minor text clipping issue in window title for when using font straying above usual line (#699)

Member variable name renamed "ID" "Id" for casing consistency

Comments

TextUnformatted() fixed clipping bug in the large-text path when horizontal scroll has been applied (#692, #246)

ImDrawList: Fixed a (rarely occuring) bug with merging with previous command + unnecessary OverlayDrawList command

Fixed TextWrapped() override wrap position is one is already set (#690)

Comments (#691)

ImFont: Allowing to use up to 0xFFFE glyphs in same font (increased from previous 0x8000)

Demo: extra (somehow duplicate) Selectables+Columns demo

Demo: Added an extra 3-way columns demo

Fixed a crash bug in stb_textedit.h (#681)

Fixed minor bug introduced in 45dacbf (#682) ...

Actually minor because nobody uses that value. Still a terrible
bug.

Comments, tweaks