Change topleft text when switching subgames, fixes #1728
Fix unit reported by TimeTaker (was always ms)
Make sure PRECISION_SECONDS corresponds to the integer 0
Right mouse button behaviour for craft/inventory
If right mousebutton clicked once then don't drop single items into slots. If
right mouse button has been clicked and held a second time, drop items as the
mouse is moved. In the second case (automatically drop/place items as mouse is
moved) only auto-drop into blank slots, or slots that contain the same item.