rolling of dice along board, DieState output, more compact repr. of
diestates in docfile (for debug)
corrected bug in makeMove (second move was done with first move's steps)
enabled pedantic compiler warnings
clean up. got rid of compiler warnings (reorders, comparisons of
signed/unsigned, etc)
more work on userSelect: select die, tile or path.
results in motion (die rolling), path drawing or deselection.

however, there are still errors ...
dice move correctly (clicking on dice, tiles or paths)
implement config load/saving to/from system-native config mechanism
(using QSettings; win: registry, linux: ~/.config/...; MacOS: some other
stuff).

signals are transmitted on settings change to gamewidget via mainwindow.
locking scene while dice move. integrated engine. using config file for
settings.

TODO: evaluateMoves seems to pollute board with phantom dice. check
inverse moves.
check, if evaluation really resulted in a move. ability to set game in
'finished' state.

still, engine produces errors. after first evaluation, possible moves
are completely wrong. it seems, something is wrong either in 'makeMove'
or in 'evaluateMoves'.
better debug output for game state
engine moves without segfaults or similar. disadvantage: it's DUMB

TODO: possibleMoves seems not to find ALL possible moves
TODO: engine doesn't want to capture opponent's dice! what's wrong with
the evaluation?
more debugging. 'possibleMoves' and 'evaluateMoves' still faulty...
engine integrated and working! next to do: check for finished game in
game-widget; implement other play modes.
move evaluation by engine is encapsulated in separate thread; however
there are still errors (must have to do with memcopies, faulty pointer
access, etc)
engine runs in separate thread via qtconcurrent. still errors:
- segfaults when no move for engine left
- stupid moves by engine (wrong evaluation perspective?)
some bugfixes

* set game to 'finished' before showing infobox
* check if candidates heap is empty before accessing 'top'
engine works! game is playable! (though, there is not yet a check
whether game is finished by a move and the finishing condition 'own king
on opponent's king field' is not yet implemented)
add dialog for preferences