Refactor - Internal ButtonBehavior() removed unnecessary boolean arg, merged into flags using ImGuiButtonFlags_NoKeyModifiers. ...

This is quite a risky change frankly but I'd rather refactor sooner than
later. Hopefully few people are using the internal functions.

Version number 1.47 WIP

Version 1.46

Renamed Window LastFrameDrawn to LastFrameActive, more correct

InputText(): always use live input data for display in read-only mode (fix #360)

HoveredId is set via a SetHoveredID() function. Added HoveredIdAllowHoveringOthers not used by default API.

Silencing inadequate MSVC warnings when exporting as DLL (#345)

Extracted a EndFrame() function out of Render() but kept it internal/private + clarified some asserts (#335)

Internal ImLoadFileToMemory() return void* instead of taking void** + allow optional int* file_size

Added missing IMGUI_API definitions in imgui_internal (fix #326)

Minor tidying, reordering functions/members/initialisation to follow same orders

Added GetDrawData() alternative to setting a Render function.

Version number 1.46 WIP

Version number 1.45

Added GetScrollX(), GetScrollX(), GetScrollMaxX() apis + demo (#246)

BeginChild() fixed missing rounding for child sizes which leaked into layout

Added optional Horizontal Scrollbar & allow user to explicitly set content width via SetNextWindowContentSize() etc (#246) ...

GetCursorPos, SetCursorPos, GetContentRegionMax,
GetWindowContentRegionMin, GetWindowContentRegionMax are now including
the scrolling amount. It PROBABLY shouldn't break anything for you, but
take note that SetCursorPosX(100.0f) puts you at +100 from the starting
x position which may include scrolling, not at +100 from the window left
side.

Turning float ScrollY into ImVec2 Scroll - no feature change, this is just to remove some syntax noise from the following commit (#246)

Added GetCurrentWindowRead() for functions that don't write to the window

Style: rename ScrollbarWidth to ScrollbarSize (sorry!)

Split tree/collapsable into internal TreeNodeBehaviorIsOpened() helper (unsure..) (#282)

Tabs to spaces

Trim trailing whitespace (#305)

Remove CaptureInputCharactersFromApp and minor cleanups (#305)

Added flag showing whether the GUI wants text input ...

Conflicts:
	imgui.cpp

ImHash: defaults seed to zero + comment.

Added GetMousePosOnOpeningCurrentPopup().

ImGuiTextFilter::PassFilter() supports string range. Added [] helper to ImGuiTextBuffer.

Prevent imgui_internal.h from being included without imgui.h (piles of errors)

IM_PRINTFARGS takes one argument. Moved pragma outside of .h (#295)