Improve the icon images by cropping selected pieces out of most of

Improve the icon images by cropping selected pieces out of most of
the main screenshots. (A few, like Map, were perfect already.)

In the process I've vertically reflected the puzzle shown in the
Pattern save file, to bring a more interesting piece of it into the
top left corner :-)

git-svn-id: svn://svn.tartarus.org/sgt/puzzles@7019 cda61777-01e9-0310-a592-d414129be87e