spit out all tags when viewing a topic
very roughly list out all tags when editing a topic
Polish tagger plugin visuals (tags now visually behave like buttons where appropriate [changing also in the related template in the discourse-theme repo]) and remove the previously added note
only show tags-selector if staff member
enable adding tags by clicking on tag list
Merge pull request #1 from sitepoint/feature/topic-tag-list

Feature/topic tag list