[Config] get SECRET_KEY from env
[Web] remove unused static files
[Web] split static and media files

This is considered best-practice in recent django versions as well as from a
operations perspective. Static files are shipped with the application and do
not change. Media files originate from untrusted sources, eg user upload,
podcast logos, etc.
Merge branch 'static-media' into design

Conflicts:
	static/css/bootstrap-responsive.css
	static/css/bootstrap-responsive.min.css
	static/css/bootstrap-theme.css
	static/css/bootstrap-theme.min.css
	static/css/bootstrap.css
	static/css/bootstrap.min.css
	static/css/font-awesome-ie7.css
	static/css/font-awesome-ie7.min.css
	static/css/font-awesome.css
	static/css/font-awesome.min.css
	static/font/fontawesome-webfont.eot
	static/font/fontawesome-webfont.svg
	static/font/fontawesome-webfont.svgz
	static/font/fontawesome-webfont.ttf
	static/font/fontawesome-webfont.woff
	static/js/bootstrap-dropdown.js
	static/js/bootstrap.js
	static/js/bootstrap.min.js
	static/js/jquery.js
WIP