Updates to naming conventions and default prefix

[mmilbrath]

Would it be feasible to also remove parenthesis from browser name to make easier to work with? The function writeXmlForBrowser currently replaces spaces with underscores and the default parenthesis in the name make it more difficult to work with on command line since they need to be escaped when copying, etc.

Example:
surefire-reports/TESTS-Chrome_51.0.2704_(Windows_10_0.0.0).xml

In addition would it possible to make an additional parameter to override the default prefix 'TESTS'. The default conventions for java surefire plugins is to use a prefix of 'TEST' (singular) and we would like to get the naming more consistent so just a bit easier to match on patterns when using the JUNIT files for other workflows.

Example
/surefire-reports/junitreports/TEST-com.mycompany.test.server.service.echo.EchoServiceTest.xml