Altered model to take university descriptions and altered related files

- University takes a description, so now the University page uses that rather than hard coded descriptions(not at all good for new data!)
- The image is also taken from the static folder as uni_name_url_Logo.jpg (e.g. University_of_Glasgow_Logo.jpg)
- Populate script added some descriptions
Renamed uni logos in line with previous commit
Added ajax functionality for signing out as well.

- Clicking the sign out button will now call an ajax function to sign you out, and then reload the current page your on instead of redirecting to home page.
- The sign in ajax file was renamed to be more suitable for its functionality
- Also fixed a minor error in the views causing university names in the breadcrumbs to be rendered as literal variables indicating encoding type and such (not very pretty)
Fixed bug in dbHelper

- Randomly retrieved all objects from the course table(woops) so that all courses were listed for each university
Added a star rating jquery plugin so that ratings can be added with a pretty looking widget
Fixed "Signed in as x" message so that it is now centred on the nav bar
Ratings are now rounded to decimal places.
Changed model names to degree and course.

- The majority of the code is refactored to reflect this, however there are still some variable names that are mismatched e.g. course = Degree.objects.get(name=course_name, university=uni)