Use the base package name as the provided value, rather than the path, because .deb packages can't start with /

Added some styles to make videos more cohesive

Name and e-mail change functionality

Conflicts:
	static/css/application.css
	static/css/marketing.css

Complex numbers now work in problems

* Parallel and exponentials in calc were broken because of this. Confirmed working
* Added test cases for the above
* Fixed a broken test case

Moved site, is_secure, etc. into render_to_string shortcut, and fixed bugs in the shortcut. We should test this pretty well, since this touches a lot of templates