Do not display highlights if game solved by hint

If a hint is used to mark the final field, gameWon is emitted. This
causes 1) the scene to be refreshed, and 2) all highlights to be hidden.

In this case, calling refresh() is unnecessary, and hover() reenables
the highlights even though they should remain hidden.
Prevent Hint action from overwriting vim-like controls

The default vim controls are HJKLBNYU, and obviously 'H' conflicts with
that.
Separate signals for game completion and won games

Since we now have a "Solve" menu option, these are two different cases.
Game completion triggers things such as disabling actions which are only
valid during a running game, stopping timers, removing highlights, etc.
Game won in turn triggers high score handling.
Adapt solve() to new gameCompleted signal

gameCompleted() already triggers these calls.
Update streaks if Solve is requested
SVN_SILENT made messages (.desktop file)
SVN_SILENT made messages (.desktop file)
Unit test infrastructure with an empty test
Implement test convenience functions and a first case

These functions should simplify the addition of further test cases.
The single currently implemented case fails (also see
https://bugs.kde.org/show_bug.cgi?id=321842.)
Add a check target to the convenience makefile
Additional streak test cases
Introduce a Streak struct with additional information

Instead of using simple ints as the internal representation of a streak,
we additionally store the beginning and end indices of each streak.
Implement the new streak generation algorithm

This algorithm is vastly simplified compared to the previous version and
should handle edge cases better.
Further streak test cases
Move streak types into nested classes

This is in preparation for merging and getting rid of a couple of
intermediate types.
Dump the LineInfo type
Rename Streak -> StreakPrivate
Rename StreakElement -> Streak
Let StreakPrivate inherit from Streak
Use vectors of Streak objects instead of Streak pointers

Streak objects are small enough to not make a real difference, and it
makes the code look much nicer.