ImFontAtlas allows loading multiple fonts into same texture. Revamped new init API for 1.30

Removed PixelCenterOffset, uncesssary

Fixed lower-right rounded triangle rendering precision. ...

PixelCenterOffset is handled very inconsistently, needs to be fixed.

Font fixes for horizontal centering within frames

ImDrawList merging commands with same texture

PushFont/PopFont changes texture at high-level in current draw list - faster

Added PushFont/PopFont API

Merge remote-tracking branch 'upstream/master' into 2015-01-truetype ...

Conflicts:
	imgui.cpp
	imgui.h

Tooltip always auto-resize. May look into max-over-xx-seconds policy later.

Allow SetNextWindowPos() to affect tooltips.

Added SetCursorScreenPos() helper (WindowPos+CursorPos = SrceenPos)

Collapsing header also honor FrameRounding

ColorEdit3: clicking on color square change edit-mode, removing color-edit mode button by default.

Added FrameRounding setting (default to 0 for now).

Fixed TooltipBg color not being honored by tooltip + no minimum tooltip size.

Fix stupid crash on fallback glyph handling (ttf branch)

TODO list update

TODO list update

Improve memory reserve policy for Clipboard/ImGuiBuffer

Fixed logging to clipboard on architectures where va_list are modified by vsnprintf (fixed #112)

Warning fixes for llvm windows 64-bits

Fixed style.WindowMinSize not honored properly.

Typos and comments

Fixed temporary glyph rectangle allocation using size much too big.

Tweak default texture width for large amount of characters.

Documentation on new font / texture get api

ImFont::GetTextureData API allow to retrieve 8/32 bits data + lazily load defaults font ...

Examples: OpenGL3 and DirectX11 back to using 32-bits texture solely for
ease of integration.

Mde it optional to new() io.Font - however it stills needs to be loaded.

TAB to spaces

ImDrawList::AddText() allows changing font