Made further changes to the find command as per #573 and #574, making alias-query aware of low-high dbref limits and changed room/exit/char filters to use inherits_from instead of dumbly assuming e.g. a room being an object with no location. Also restructured the code a little.
Fixed nasty lookup bug when querying for multi-word fuzzy matches using mysql. Resolves #527.
Fixed so CmdIRC2chan correctly handles deletion by botname and not just by dbref. Resolves #572.