First pass at updating Perl6::Grammar

Builds! And passes something like 85% of spec tests!
Merge branch 'nom' of git://github.com/rakudo/rakudo into stdsigspace
Get up to spec

Remaining issues: Occasional 'method not found for object of type NQPMu'
where 'Null regex' error should be made.
Merge branch 'nom' of git://github.com/rakudo/rakudo into stdsigspace
Let null regex exceptions get thrown
Merge branch 'stdsigspace' of https://github.com/Mouq/rakudo into nom
Merge branch 'nom' of github.com:rakudo/rakudo into nom