Chillin' Out, 'Laxin'

* Add real parallax effect to splash page, with appropriate refactorings
    of the CSS.
* Change border-radii to 3px over 4px. Why? Not sure.
* Tweak backgrounds ever so slightly.
* Fix squished masthead images---pad only text and buttons, make the
    images full-bleed.
Update Sprockets, Deploy Scripts
Remove ng_annotate config from staging.
Hand-annotate Angular modules.
Update Gemfile.lock.
Annotate MailerPreview Angular modules.
Merge branch 'feature/subtle-parallax' into develop

* feature/subtle-parallax:
  Annotate MailerPreview Angular modules.
  Update Gemfile.lock.
  Hand-annotate Angular modules.
  Remove ng_annotate config from staging.
  Update Sprockets, Deploy Scripts
  Chillin' Out, 'Laxin'