Migrate from Cheetah to Django template system

Compiled templates are an unnecessary pain in maintance and
packaging. If each module is to bring its own templates, compiling
them in the build process becomes unnecessarily more complex. The
current state of template mess can somewhat be attributed to this.

Cheetah only partially supports dynamic templates. It does not support
inheritence of dynamic templates. From its documentation: "There is no
support for extending from a class that is not imported; e.g., from a
template dynamically created from a string. Since the most practical
way to get a parent template into a module is to precompile it, all
parent templates essentially have to be precompiled."
Remove steps for compiling templates
Dont gitignore compiled template files
Remove cheetah as a dependency
Update documentation on templates to reflect Django templates
Update LICENSES file to reflect template changes
Remove unnecessary layer of abstraction over template rendering
Allow placing templates inside module directories
Convert pagekite introduction page to templates
Convert right sidebar menus to templates
Convert OpenID sidebar to template
Convert add/edit user sidebars to templates
Convert firewall page to template
Convert system page to template
Convert diagnostics pages to template
Convert apps pages to templates
Convert help pages to templates
Convert file explorer page to template
Convert sharing pages to templates
Convert privacy pages to templates