New reference panel: Allow filtering with globbing (including negative filters)

Created by: mrnugget

Google CS allows filtering references with globbing and excluding files.

A nice and simple way to implement the same behaviour would be to use globbing including negative predicates to get the same functionality.

• foo/bar/* matches all files starting with foo/bar
• foo/bar/*.go matches all files starting with foo/bar and ending in .go
• !*_test.go matches all files that do not end in _test.go