Merge pull request #349 from sgarrity/bug-781030-styleguide

Bug 781030 styleguide
Loop-a-doodle-doo
Merge branch 'refs/heads/style-guide'
Link to the new style guide
Add back in download links.
Merge branch 'refs/heads/style-guide'
Fix links in video page.
Merge branch 'style-guide'
Merge remote-tracking branch 'refs/remotes/craigcook/about-mission'
Fix bug where set literal was used instead of tuple.
Update SMS form error message.
Fix Fx mobile links.
Merge branch 'master' into sms-android-good-branch

Conflicts:
	media/css/sandstone/buttons.less
Fix button classes.
Clean-up issues from review.
Fix issue with device and learn more links on thankyou page.
Updates in response to feedback

* Changed video poster image
* Changed video overlay
* Removed Play link from thank you page
Merge pull request #2 from craigcook/bug-774861-sms-page

Updates in response to feedback
Email console backend should only be used on local environments

bug 780913

Conflicts:

	settings/base.py
Corrected subscription stop message and number