feature: better theming backend support
- replaces static_views system with better theming with overrides

long version: this modifies the way ubersystem searches for templates in the themed/ dir

here's the search order for the file:   'themed/prereg.css'
- first looks in 'themed/{current_theme_name}/prereg.css
- if not found, looks in 'themed/common/prereg.css'

Now we can override any file in common with stuff in specific theme dirs.

In the future, I want to unify this with the static/ dir, but for now this will work.  To unify both of them means we have to override more than just the templates and know when to process templates vs when to just serve up non-templated files (like JPGs and PNGs)
fix absolute path issues

current solution wasn't working for inclusion of base-admin.html on multiple subdirectories of the URL.

For now, we're going to use the absolute path when including base-admin.html

Created a custom tag to deal with this, 'absolute_path'

Deleted no longer needed THEME_VIEW_DIR since we can just do 'themed' from now on
redo theme support in a non-dumb way

Man. what was I thinking? Discovered django had a really easy way to do this with TEMPLATE_DIRS, so I did that.

Now we can override ANY template, not just the ones in themed/ and/or static_views/ dir.

example:  templates_themed/preregistration/disclaimers.html overrides th same file in templates/preregistration

so:
- renamed themed/ back to static_view/
- created a new dir named templates_themed/
- setup configspec.ini to setup TEMPLATES_DIR
Merge branch 'master' into ftr_theme_inheritance
move build_absolute_path() to state class
themeable fixes per Eli's code review
- render now one function that converts input to a list if it's not one already (listify)
- more appropriately named screw_you_nick() function
rename args to path_args for readability
Merge pull request #249 from EliAndrewC/ftr_theme_inheritance

feature: better theming backend support