Merge branch 'master' into navigation ...

# Conflicts:
#	imgui.cpp
#	imgui.h
#	imgui_demo.cpp
#	imgui_internal.h

Renamed GetItemsLineHeightWithSpacing() to GetFrameHeightWithSpacing()

Added GetFrameHeight() function (used to be SmallSquareSize internally)

Internals: Added GetSmallSquareSize()

IsWindowFocused() refactor will flags. (#1382) ...

Marked IsRootWindowFocused() as obsolete in favor of using IsWindowFocused(ImGuiFocusedFlags_RootWindow).
Marked IsRootWindowOrAnyChildFocused() as obsolete in favor of using IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows).

Demo: mouse dragging demo tweaks

Reordered ImGuiHoveredFlags to match upcoming ImGuiFocusedFlags (#1382)

Font documentation update (#1498)

Internals: ParentWindow is now NULL for non-child windows and means what everyone expects.

Internals: Removed misleading GetWindowParent() function. + renaming to clear confusing.

IsWindowHovered(): split ImGuiHoveredFlags_FlattenChild into separate ChildWindows and RootWindow flags. Allowing more combination and a better symetry with IsWindowFocused() flags. (#1382)

Alignment + removed comments

Renamed ImGuiTreeNodeFlags_AllowOverlapMode to ImGuiTreeNodeFlags_AllowItemOverlap. (#600, #1330)

Internals: Renamed ImGuiButtonFlags_FlattenChilds -> ImGuiButtonFlags_FlattenChildren, ImGuiButtonFlags_AllowOverlapMode -> ImGuiButtonFlags_AllowItemOverlap

Comments (#822)

Merge branch 'master' into navigation ...

# Conflicts:
#	imgui.cpp
#	imgui.h

Obsoleted old functions: SetScrollPosHere (marked obsolete in 1.42, July 2015). GetWindowFont(), GetWindowFontSize() (marked obsolete in 1.48, March 2016)

Added an implementation of SetItemDefaultFocus() in the master branch for combo patterns to use and be more forward-compatible. (#787)

alloca fix to allow Clang with Microsoft CodeGen path

Replaced obsolete function with new one.

Merge branch 'master' into navigation ...

# Conflicts:
#	imgui_demo.cpp

Demo: Tweaks and spacing. Stopped using rand() function in demo code.

Demo: About box tweaks.

ImFont: Added GetDebugName() helper.

Exposed BeginCombo() publicly.

Sorted typedefs/enumations forward declarations in imgui.h

SetNextWindowContentSize() adjust for client->window size, but the fate of borders isn't really clear for now (until now we always tried to make borders not affect layout, so if we want a 200x200 fully visible space with borders and zero window padding user need to include the borders) (#1490)

Scrollbar: Minor simplication of the code using InnerRect data.

Internals: window->InnerRect includes removal of borders so it'll be easier to use from other locations.

Demo: Added "No close" option.