Next iteration of the Tag feature

Larger feature requests for the tag module will be collected under this epic and at some point in Q1 2011 we will engage the makers of Tag to possibly get this developed by them.

The goal of the next iteration of Tag is (so far):

• Increased usability (auto complete)
• Support synonyms/aliases
• Support more complex searches (AND, OR, NOT)
• Options for monitoring tags for users