For manage tags there is 3 tables:

- Tags
- TagsUsers
- TagsModules

The Tags table contain the tag itself.
 - id    = Id of the tag.
 - word  = The word of the tag.
 - crc32 = The crc32 converted integer of the word.
           This is for incress the search.

The TagsUsers table contain the relation between the user and the tags.
 - id     = Id of the relation user-tag.
 - userId = The Id of the user.
 - tagId  = The Id of the tag. (See Tags table).

The TagsModules table contain the relation
between the module-itemId and the user-tag relation.
 - module = Module name.
 - itemId = Id of the item.
 - tagUserId = Id of the relation user-tag. (See TagsUsers table).