* prototyping enhanced dnd features

* improve dnd demo using new utils

* dnd stuff

* finish up dnd improvements

* remove unused code, fix timestamps

DatePicker separate disabled color

Separate disabled color from the selected date to the truly disabled dates in another month. Move setting col/styles after we are done getting them.

Co-authored-by: Philippe Kehl <philippe.kehl@fixposition.com>

add PrimUnreserve to AddTextVertical when the render characters is less than the expected characters (fixes utf8 issues)

make context menus open on single right click, move ImPlotInputMap out of public API (see implot_internal.h) (#170)

* Allow second and third axes to have labels

* Handle both axes in one loop

* fix compiler warnings, add ImPlotAxisFlags_NoLabel

* fix bug when y2 label hidden

Co-authored-by: epezent <epezent@rice.edu>

Several `CollapsingHeader()` use same label as `BeginPlot()`. This creates an ID collision, which confuses Dear ImGui testing engine. Added `##` in `CollapsingHeader()` label are included in ID calculation, but discarded when rendering. This gives affected `CollapsingHeader()` a different ID and solves ID collision.

Co-authored-by: Yan Zaretskiy <yzaretskiy@stoneridgetechnology.com>

Co-authored-by: Philippe Kehl <philippe.kehl@fixposition.com>

* prototyping equal axes

* equal proto

* more refactors

* euqal axes almost perfect

* fitting axis equal working

* fitting axis equal working

* finish equal axis