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
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.
Give null user a nil id
Tweak home page styles. Use pink for links.
Tweak 'try it' on homepage
Fix minitest class name
Stub in onboarding process
Add note about dashboard improvements