Baseuri master

Please consider to pull this branch: It allows to deploy snorby under a "base uri", that is an application specific url prefix. This is sometimes required to work in situations where it is impossible to deploy an application to the root of a virtual host.

It introduces an additional baseuri configuration parameter to the snorby_config.yml file. The baseuri is then used as a prefix to all urls generated via ruby or javascript. For the JS side, a new global var named baseuri is generated to be used by all js code generating urls programatically.

The branch is based on master and NOT the current development branch.

I am using this branch behind a reverse proxy pointing to /snorby/ to the snorby installation using mod_passenger and a baseuri set to "/snorby" successfully.