StonesLayerDelegate now handles cross-hair state correctly (fixes #244)
interactive UI elements are now disabled while stone-placing gesture is in progress (fixes #243)
user can now make a move when viewing an old board position and the game has ended (fixes #246)
stones no longer temporarily disappear from view while dragging a new stone (fixes #245)
app no longer crashes if after loading a game it is the computer player's turn (fixes #247)
permanently enable TTY logger, but only with log level WARN
final tidying up for release 1.1.2