SiteStats (2.1)

Now, 2.0 --> 2.1 changes doesn't include any "big feature" or, in other words, a "visible" feature to the end-user:
Lots of bugfixes
Code clean up
Dependencies upgrades
Static code review
Meet Sakai 2.7.0 requirements: pom changes, licensing, assembly, mvn release plugin, etc
Compression of css/js
EntityBroker event aggregator metrics
Review of wordings on labels (Overview page)
Review of minor incompatibilities with Sakai Style Guide (links)
Disable report exporting from sakai.properties