grouping.extras: new word group-by, like sql GROUP BY but is order-preserving
grouping.extras: group-by is faster with vectors.
grouping.extras: fix stack effect names for (group-by).
Revert "alien.libraries: dlopen should handle resource:-paths"

This reverts commit cc663fff88fa7321af6deea424890128d3b0bc07.

Conflicts:
	basis/alien/libraries/libraries-tests.factor