My favourite kind of patch, from James H: one which decreases the

My favourite kind of patch, from James H: one which decreases the
amount of code. James has ripped out the solver's version of
check_complete(), in favour of using the one I wrote for the
game-playing UI. My one checks connectedness, which means that the
solver will now not believe non-solutions to puzzles where
connectedness becomes a difficult issue. Examples of game IDs which
are now solved correctly but were previously not are 5x3:ubb and
7x7:ajfzmfqgtdzgt.

[originally from svn r7362]