attempt not not count tags assigned to items that are not viewable
option for getAllTagsUnique to exclude unassigned tags or assigned to protected items (intended for tag_suggest that should not suggest tags you can't view at all)
Typo…
Follow up fix for tagsuggest frontend/backend and caching of the two different tag sets.
Merge pull request #876 from zenphoto/tags

Tags fixes - fix #867
Merge remote-tracking branch 'upstream/master'
The performance implications of the upstream change are enormous. If it is really important to filter tags that have protected targets it should be done during the tag list processing. But even that will cost terribly and probably be unacceptable for "normal" use.

Conflicts:
	zp-core/functions.php
	zp-core/zp-extensions/tag_suggest.php