Add joined tracking for onboarding
Reorganize top nav
Make dev backdoor more useful
Each view implements the 'container' div.
Merge pull request #1647 from jbcden/fix_iteration_nums

fix submission numbering bug
Merge pull request #1643 from tbloncar/tb-container-placement

Each view implements the 'container' div.
Add user mentions in nitpick form:
- Add Users search API endpoint
- Add query_user API helper
- Test new API endpoint
- Add watch to data.body in Markdown Controller (Angular frontend)
- Test Markdown Controller
- Add atwho.js for user mention capability
Tweak about page
Refactor development backdoor
Fix timezone issue in test
Merge pull request #1648 from fluxusfrequency/1637-user-mentions

Add user mentioning in nitpicking form
Gah. Remove assume
Put the backdoor back in
Give views page headers. Add typography stylesheet.

Introduce page header section in each view. Add typography stylesheet to
house text-specific styles. Use 'Source Code Pro' for header font.
Merge pull request #1649 from tbloncar/tb-page-headers

Give each view a page header.
Give null user a nil id
Tweak home page styles. Use pink for links.
Merge pull request #1652 from tbloncar/tb-home-page

Tweak home page styles. Use pink for links.
Tweak 'try it' on homepage
Fix minitest class name