[svn] Commit various hash table changes:

[svn] Commit various hash table changes:

* hash.c (hash_table_map): Allow deletion and change of the
element processed by MAPFUN.
(string_hash): Use the function from glib.
* hash.c (hash_table_remove): Rewrite to actually clear deleted
entries instead of just marking them as deleted.

Published in <sxsu23tvdur.fsf@florida.arsdigita.de>.