SpockConfig can include/exclude by regex pattern string.

Please consider adding this to Spock.  You [mentioned](https://groups.google.com/d/msg/spockframework/DQFTj9dXD2Y/HPJqTISBiocJ) that it would be good to do.

The regex pattern is matched against the simple name
of the annotation, spec, or feature.  This addresses
http://code.google.com/p/spock/issues/detail?id=184

Also added to new_and_noteworthy, and updated javadoc in 
IncludeExcludeExtension and RunnerConfiguration.  Removed an apparently 
obsolete part of the example from the latter, because it didn't work 
when I tried it, and there are no specs for it.

I would have liked to use GrailsTestTargetPattern with its AntPathMatcher,
but that seemed out of scope for Spock.