Popups: calling OpenPopup() on already open popup doesn't close it's child (#126) ...

It think it makes more sense? Maybe?
Note that calling OpenPopup() every frame probably doesn't make sense.

Tweak BeginMenu() code

Moved CloseInactivePopups() and tweaked.

Merge remote-tracking branch 'upstream/master'

Define STBTT_DEF extern when STBTT not compiled with ImGui.

Added BeginPopupContextVoid() helper for completeness (#126)

Fix to allow opening popup from a left-click on void or another window (because left-click would normally override focus immediately) (#126) ...

Neither appears to be really useful frankly.

BeginPopupContextWindow() rearranged and clarified parameters (#126)

Popup taking focus deactivate focused widget of other window (#126) ...

e.g. focus InputText(), open contextual popup, input text used to stay
focused

Tracking ActiveIdWindow along with ActiveId

Added BeginPopupContextItem() / BeginPopupContextWindow() (#126)

Fixed GetId()/BeginPopup() accessing current window in "append" mode

Added IsAnyItemHovered() public helper.

No minimum size for popups

Tweak context menu example

Added context menu example on a DragFloat widget

Tweaks

WIP Menus: Reverted f26de46 for now (#126)

Oops

ItemWidthStack can be empty, to remove one allocation per window

Store common stacked settings contiguously in memory to reduce cache misses & unnecessary heap allocations

Added PushButtonRepeat() / PopButtonRepeat(). REMOVED third 'repeat_if_held' parameter of Button() !

Added configurable io.KeyRepeatDelay, io.KeyRepeatRate

Simplified some widget code, moving alignment to RenderTextClipped()

Reordering parameters of internal RenderTextClipped()

Button centering left to RenderTextClipped function.

Button() closes active popup (#126) unsure about that

Refactor Button() and SmallButton() into a shared function ButtonEx()

Spacing + untabify

EndGroup() carries on the text base offset from the last line of the group (sort of incorrect but better than nothing)