reworked client side app

- switched from hogan.js to swig (http://paularmstrong.github.com/swig/) for django-like templating. this saves a lot of client side code (eg. date formatting, but also context preparations/lambdas)
- updated libraries
updated built version of client side app
fixed "load more" behaviour (broken due to a change in backbone)

- don't display "none" for maintainers/contributors, instead don't render the lines at all