views_handler_dependencies buggy when modules define stuff for tables that aren't theirs

Symptom: location module was already added as a dependency for nearly every feature

Cause: location was listeded as module for node and node_revisions for views_handler_dependencies. Location defines joins from node/node_revisions to location tables. so isset($info['table']) for node table for location_views_data returns true. And since location runs later, it takes the depedency, so anything with a node view gets added as a dependency. Ouch!

Patch adds some additional checking; not sure it's foolproof, but better than current I think.