Version that stops looking for U after 3 attmepts, closing it.
If it gets stuck on island (i.e.) after a goAcross() it does another goAcross when it
comes back to same position.
GoHome implemented.
backToStart changed to isHome and is bool. Cancer execvation moved to closeMap()
Fixed compilation errors
Merge branch 'master' of github.com:/hansfilipelo/MapMaster2001