New option --limit-commands for regress.pike

[gunnar]

This patch adds a --limit-commands (short -l) option to regress.pike. As argument this takes a comma separated list of GTP commands, then only runs tests with those commands. E.g.

./regress.pike -l attack,defend

will run all tactical reading tests in the entire testsuite but no other tests.

As a bonus this feature invalidates any need to have semeai.tst split between different commands, so the patch also reorders semeai.tst strictly numerically.

[gunnar]

New option --limit-commands for regress.pike and semeai.tst reordered.