Updated grunt script so it can copy the build files to the right location.
Updated to latest Pixi build (can do away with our own local patch now).
Group.sendToBottom(child) is the handy opposite of Group.bringToTop()
Group.moveUp(child) will move a child up the display list, swapping with the child above it.
Group.moveDown(child) will move a child down the display list, swapping with the child below it.
Fixed issue where Image, Sprite, etc wouldn't call preUpdate or postUpdate of its children.
Fixed issue where renderOrderID wasn't being assigned correctly, causing the Input Handler to be unable to select the "top" item on a display list (would all default to zero)
Fixed issue where Stage would assign renderOrderIDs in reverse, should be in sequence.
Fixed issue where objects where checking World for the currentRenderOrderID by mistake instead of Stage.
Basically, input handling works a lot better now for Groups and nested objects :)
Merge remote-tracking branch 'upstream/1.2' into 1.2