Global filter ignore rule by file name

[mihaisoloi]

For now the global filters ignore by error message patterns

scalacOptions += "-P:silencer:globalFilters=[semi-colon separated message patterns]"

it would be great if we could ignore by file name patterns as well.

This way we could handle issues where the compiler is used to generate some classes. An issue you can't use the silencer for is this:
playframework/playframework#7382

[ghik]

Fixed in 1.3.0