Minor UI enhancements

• Added support for [small]text[/small]
• Added auto completion to tag list presenter
• Added showing tag suggestions on click (until now, it was shown only when typing, while clicking revealed just siblings)
• Added tag suggestions and siblings synchronize to what user types
• Added gray-out for used tags in the autocomplete
• Moved tag suggestions before tag siblings
• Fixed tag editing didn't trigger tag suggestion cache update
• Changed post edit form to be wider
• Fixed autocomplete staying even after hiding the tag input (occurred during presenter change)
• Fixed author showing up in the history for posts uploaded anonymously