too large collection arrays are now avoided. By default, the biggest
collection index is 7. larger collections are dumped into a commons
directory, but cannot yet be used. Bevore doing a dump, the collection
is splittet into a part which has only root-references, and stored back
to the collection; the remaining part goes to commons
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@3426 6c8d7289-2bf4-0310-a012-ef5d649a1542