Adds tagging speed metrics tracking

Tracks time user spent tagging shred in milliseconds. See #28 for
details.
closes #5
Merge pull request #37 from z4y4ts/master

Adds tagging speed metrics tracking
Merge branch 'master' into 5-service-page

Conflicts:
	settings.py
	static/scripts/base.js
Merge branch 'master' into 5-service-page
email changed to username
Merge pull request #38 from dchaplinsky/5-service-page

5 service page
merge with master