Change name of RunInitialScan
Update Godeps
Fixes to main function

* Small cache object limit was wrong.
* Remove unused Article type.
* Don't load tags file at startup anymore, since there's no need to
  keep it persistent in memory.
Improve Tags handling.

NewTags now automatically reads the tags file or generates the tags
from the posts directory, if needed..
Add helper functions for adding a new post to an existing tags structure.
Finish TagsByPopularity.
Beginning of fswatcher