Made AlignFirstTextHeightToWidgets() saner and faster (still disliking its name very much!)

Merge branch 'master' into navigation

Nav: Menus and popups now have move request wrap around vertically (using the move request forward thing added recently). (#787)

SetKeyboardFocusHere() added assert to prevent passing values smaller than -1 as we may have to outlaw them (I think nobody was using that)

Removed obsolete comment.

Merge branch 'master' into navigation

Styles: Added ImGuiStyle::ScaleAllSizes(float) helper to make it easier to have application transition to e.g. High DPI with a matching style.

Nav: Added code to render thin highlight type. (#787)

typo

Nav: Highlight clipped within host window then extruded out. (#787)

Nav: Selectable(): activating selectable also sets NavId + removed the MouseDelta test (added in 43ee5d7, #323) as I don't think it is needed. (#787)

Nav: Added NavMoveResultParentId internal info to record when the parent/context of a given NavId. Useful for various algorithms (currently looking at range selection stuff) (#787)

Nav: Added NavJustNavigatedId internal info to record when we land on a given item after a navigation request, useful for various algorithms (currently looking at range selection stuff) (#787)

Changed the internal name formatting of child windows to use slashes as separator, more readable.

Metrics: Draw window bounding boxes when hovering Pos/Size. List all draw layers, trimming empty commands like Render() does.

Nav: Fixed a crash introduced yesterday.

Nav: Allow to collapse tree nodes with NavLeft and open them with NavRight (#787, #1079)

Nav: Disabled the final axial check when considering candidates in most situations except menubars. ...

It's definitively undesirable inside Menu as we want to catch nav request failures reliably.
I think it may be considered as an option if we find this desirable i some circumstances. Right now ideally I'd remove it totally but with current scoring setup, without it we can't easily reach the Window Close button. (#787)

Nav: It's now possible to navigate sibling of a menu-bar while navigating inside one of their child. If a Left<>Right navigation request fails to find a match we forward the request to the root menu. (#787, #126) ...

Currently the sibling menu is isn't automatically opened, that's still left to it (and even that can be anoying in Windows when the first menu-item is a child menu)

BeginMenu(): fixed logic to distinguish vertical menu from one layed out in a menu bar. Makes MenuItem() in a regular window behave more consistently, and this will be also needed by upcoming menu-navigation changes in the nav branch. (#126, #787)

BeginMenu(): fixed logic to distinguish vertical menu from one layed out in a menu bar. Makes MenuItem() in a regular window behave more consistently, and this will be also needed by upcoming menu-navigation changes in the nav branch. (#126, #787)

Nav: Comments

Nav: Fix typo from 9712a81

Nav: Minor tidying up (adding local variables to be a little more sane).

Nav: Renamed internal field.

Nav: Rectangle rectangle stored per window and per layer as well. Makes things simpler, allows enable us to visualize more data.

Nav: Marked misleading/broken code that will never execute.

Nav: Fixed menuitems/selectable on menu layer (layer 1) from storing themselves in wrong layer of LastNavIds when hovered.causing inconsistencies and bugs when hovering menu with mouse then pressing ALT to return to layer 0). ...

NB: this is not a new bug introduced by the previous commit (which is related to nav layers), bug has been there for a while. (#787)

Nav: Store per-window last nav id also per-layer so we can easily query them for menu navigation code. (#787)

Merge branch 'master' into navigation ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h