Fix using IsItemActive() after EndGroup() or any widget using groups (#840, #479)

Merge remote-tracking branch 'origin' into 2016-07-navigation

Style: Added ButtonTextAlign, ImGuiStyleVar_ButtonTextAlign (#842)

Refactor text alignment options to use ImVec2, removed ImGuiAlign (#842, #222)

Internal RenderTextClipped() merged optional/rate clip_min* clip_max* into clip_rect*

Comment

Tidying up PushStyleVar/PopStyleVar() a little more (#842)

Refactor PushStyleVar/PopStyleVar so it is constant time + can receive integers (yet unused) (#842)

Shutdown() clear out some remaining pointers (#836)

Metrics: Displaying window position + moving extraneous line in IsPopupOpen().

Fixed EndGroup() not restoring offset properly. breaking SameLine() offset (caused by 954c890) (#829)

Fixing minor english typos (#827)

TODO list

Fixed assert triggering when a window has zero rendering but has a callback (#810)

Examples: Renaming opengl_example/ to opengl2_example/ for clarity (1/2 because git)

Merge remote-tracking branch 'origin' into 2016-07-navigation

ImFormatString() Fixed an overflow handling bug with implementation of vsnprintf() that do not return -1 (#793)

Nav: Comments. Fixed two -Wall warnings. Removed unused function. (#787)

Nav: Fixed Selectable() crash introduced earlier today in 43ee5d73 + added comments/assert (#323)

Nav: NavActivateId, NavInputId are no repeat actions. Repeat buttons handle it themselves already anyway. (#323)

Nav: Removed unnecessary test following 49ca1c2 (#323)

Nav: InitDefaultRequest saves a fallback item so PadMenu on a collapsed window gets us to the collapse button (#323)

Close button submitted after collapse button. Should have no effect. Consistent with expectation & will be used as fallback for nav (#323)

Nav: Undo 87eb749cbc, agressively including nav focus test in IsItemHovered() (#323)

Nav: Fixed nav highlight clipping (affected non non-menu items within menubar) (#323)

Nav: Process and apply mouse move request immediately after move request result comes (#323)

Internal tidying up, moved code to CalcNextScrollFromScrollTargetAndClamp() so it can be reused by upcoming nav code.

ImRect: Added Translate() helper, removed redundant and misleading Reduce()

Added IsItemHoveredOrFocused() (provisional name), better handling of popup/tooltip positioning when using mouse+nav (#323)

Nav: Fixed entering child with PadActivate not setting ActiveIdSource to Nav (#323)