Fixed a few zealous warnings.

Removed need for -Wnocast-qual on modern Clang/Xcode as a token of good behavior. Unfortunately the old stb_ decompress code is a little const clunky. + warning fix in stb_textedit which is already in master afaik.

Fixed Clang zealous cast-call warning (on par with GCC) which decided to warn against explicit C-style casts now.

imconfig: Added IMGUI_STB_TRUETYPE_FILENAME, IMGUI_STB_RECT_PACK_FILENAME + documenting IMGUI_DISABLE_STB_XXX flags and hiding IMGUI_STB_NAMESPACE which is misleading. ...

Fixed typos in todo list.

ImDrawList: Added Clone() helper function.

Update TODO list, minor fix in Readme, comments, Clang -Weverything warning fix in imgui_draw.cpp under Windows.

Style: CloseButton() now display a proper cross. Using Button colors for background. Removed ImGuiCol_CloseButton, ImGuiCol_CloseButtonActive, ImGuiCol_CloseButtonHovered as the closing cross uses regular button colors now. (#707)

ImFont: Added FindGlyphNoFallback. Fixed MergeMode broken by 1ef1acb

Merge branch 'master' into font_offset

Font: Fixed MergeMode adding duplicate glyphs data instead of reusing existing (broken by 072d6d8)

Fonts: Fixed debug name not being zero-terminated if longer than storage buffer + made buffer slightly longer as well.

Removed redundant semi colons. (#1653)

Comments, FAQ update.

Renamed ImGuiStyleVar_Count_ to ImGuiStyleVar_COUNT for consistency with other enums. Added

ImDrawList: Better looking non-AA rectangle (lower-right corner and rounding). (#1646)

ImDrawList: PushTextureID(): Removed unnecessary param by reference.

Renamed misleading ImGuiMouseCursor_Move to ImGuiMouseCursor_ResizeAll. SDL: Fixed cursor. (#1626)

ImFont: stb_truetype now rounding Ascent/Descent the same way as freetype does, they seem to vertically align better this way.

ImFont: DisplayOffset.y defaults to 0 instead of +1.

Comments, moved ImFontAtlas::Flags to "public" area.

ImFontAtlas: Added ImFontAtlasFlags_NoPowerOfTwoHeight, ImFontAtlasFlags_NoMouseCursors flags. (#1613)

ImFontAtlas: if stbtt_PackBegin() because of failing allocation we return a little more nicely. (keeps Coverity static analyzer happy!)

Styles: Comments and re-ordered.

Updated version to 1.60 WIP to emphasis on the addition of required calls CreateContext/DestroyContext + merged the massive Navigation branch (#1565, #787)

Merge branch 'master' into navigation

Moved extra_fonts/ to misc/fonts/. Moved .natvis file to misc/natvis/ (#1569)

Nav: Style: Improved display of windowing highlight (for focus selection via PadMenu or Ctrl+TAB). (#787, #707)

Merge branch 'master' into navigation

ImFontAtlas: Added TexUvScale (= 1.0f / (float)TexWidth, 1.0f / (float)TexHeight)

ImFontAtlas: Moved mouse cursor data out of ImGuiContext, fix drawing them with multiple context. Also remove the last remaining undesirable dependency on GImGui in imgui_draw.cpp, finishing the work recently done with ImDrawListSharedData. Hurra! (#939)