Elements work like they've always done, this just moves the commonly
used components away from the global namespace.
The qmldir file still does something, although at this point it is
unknown exactly how it's used and whether or not it could be changed to
simplify imports across the block.
Valve's official terminology are "Room Setup" and "Tracking Universe". Changed our usage of "Playspace" to "Room" for clarity with the upcoming Room-Turn feature and existing Room-Drag feature when compared to nomenclature for other tools that exits out there.
Also slight clean up in readability of movecentertab's action functions.