Nav: MoveRequest doesn't affect io.NavUsable so that navigation failure doesn't trigger false positive & not needed (undo part of 3cc1419df)

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

SameLine() with explicit X position is relative to left of group/columns (ref #746, #125, #630)

Nav: making io.NavActive more suitable for end-user detecting if they should pass inputs to game (#323)

Nav: Calling SetItemDefaultFocus() doesn't make mouse cursor dirty if nav highlight is off (#323)

Nav: programmatic call to SetKeyboardFocusHere() doesn't quality as a nav input (doesn't position mouse) (#323)

Nav: Split _NoNav window flag into _NoNavInputs and _NoNavFocus (#323)

Nav: Fixed Collapse icon disappearing when Nav is disabled (since b2aaab8) (#323)

Tidying up

Nav: first committed pass for manual moving and manual scrolling (after a bunch of attempts) (#323)

Clarifying that MovedWindow* apply to mouse moving only

Nav: Fixed navigating outside of current scrolling bounds (bug from 0cc20fc) (#323) ...

+ spaces

ImRect: fixed Clip() function being the other way around (INTERNAL API BREAKING CHANGE- wasn't exposed, hoping nobody uses that) + actually fixes the function behavior.

Nav: ActiveIdAllowNavMove -> ActiveIdAllowNavDirFlags for more flexibility (nav up/down typically allowed on a single-line text input) (#323)

Nav: Renamed private ImGuiNavDir_ enum to use left/right/up/down to be consistent with key enums (#323)

Nav: CalcListClipping/ImGuiListClipper: fix to ensure we can navigate clipped lists (#323)

Nav: not activating widgets with NavActivate when NavMenu is held (#323)

Nav: collapse button is interactve, allow collapsing, tidying up, resize speed takes account of framebuffer scale (#323)

Shallow tidying up ctrl+wheel scaling code in NewFrame()

Tidying up default clipboard handler for non Windows-OS

Fixed bad merge

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

InputTextEx: got rid of unnecessary locals.

InputTextEx(): more shallow tidying up, still being cautious with this function

InputText/IO: Got rid of individual OSX options in ImGuiIO, added io.OSXBehaviors (#473, #650)

InputTextEx(): minor tidying up

InputText(): minor tidying up/simplification following changes for osx style improvements (#650)

Merge branch 'add-osx-homeend-keys' of https://github.com/michaelbartnett/imgui into michaelbartnett-add-osx-homeend-keys

Navigation: Tap NavMenu to access menu and close buttons, hold to focus/resize (#323) ...

Introducing a concept of NavLayer to filter navigable items

Navigation: Renamed ImGuiKey_NavWindowing to ImGuiKey_NavMenu (#323)