support for phantomjs running

There were some synchronization issues with phantomjs, these were fixed in HtmlUnitBasedScriptInstrumenter.java and ScriptData.java

I also added better support for jasmine-maven-plugin if it was executed with phantomjs.
If you use jasmine with phatnomjs it runs the tests through a webserver, and saga also
used this server to calculate coverage. Because of this, total coverage report was not possible,
since it saw only the files tested by jasmine.
To solve this, I expanded FileSystemSourcePreloader.java. If sourceDirs is defined in pom.xml, then it is used as full source directory.