feat(LCOV): LCOV Branch support and fixes to lcov parsing

* Adds support for branches in LCOV.
* Moves to CoverageMeasuresBuilder instead of plain metrics.
* Adds a bigger LCOV coverage report on the same source files in [example project](https://github.com/SonarSource/sonar-examples/tree/master/projects/languages/javascript/javascript-sonar-runner-JsTestDriver)

I know this covers somehow  #3 and #4, but I've also added tests to cover the changes as well as an update LCOV coverage report.

I've opened a JIRA ticket for this request: [SONARPLUGINS-2695](http://jira.codehaus.org/browse/SONARPLUGINS-2695)
 
I hope I've done all I can to get this merged asap.