Merge branch 'jn/userdiff-perl-updates'

Merge branch 'jn/userdiff-perl-updates'

* jn/userdiff-perl-updates:
  userdiff/perl: tighten BEGIN/END block pattern to reject here-doc delimiters
  tests: make test_expect_code quieter on success
  userdiff/perl: catch sub with brace on second line
  userdiff/perl: match full line of POD headers
  userdiff/perl: anchor "sub" and "package" patterns on the left
  t4018 (funcname patterns): minor cleanups
  t4018 (funcname patterns): make configuration easier to track
  t4018 (funcname patterns): make .gitattributes state easier to track