Polished Admin UI

* Added Twitter Bootstrap
* Fixed a bug in Session class
Removed Admin class
Extracted session list into a class that loads data from file
Started implementing web page for users
Fixed some bugs with it
Removed debug prints
Maven now compiles for java7
Cleaned up the user session code
Fixed formatting of Session.java
Added more sessions to the default data set
Fixed User sessions

Fixed user session filters
Fixed user session links
Merge pull request #7 from GUTeamU/Spring

Spring