A bit of cleanup in Configure.pl

Cleaned up whitespace and changed quotes to make perlcritic a little happier.
proper error message for usage of 'do...for'

https://rt.perl.org/rt3/Ticket/Display.html?id=102652
Add Bool method to Capture

Right now, defined captures evaluate to `True`, but empty captures should probably be `False`.
First snapshot of DUMP extension work; lots of debug output trying to track down apparent marshalling issue.
Replace broken pir::perl6_current_args_rpa__P() call with nqp:: equivalent, stopping RPA -> Parcel looping
Remove/clean up debugging output a bit
Improve DUMP output a bit for Bool, Parcel, Range, and a few misc cases
Minor whitespace cleanups
Add comment with desugared version of $attr.get_value(self), which jnthn believes might fix an edge case later
WIP on EXPORT returning a hash.
actually return a Hash from EXPORT
type check result from &EXPORT
fix spectests
run EXPORT subs always when present

not just when an argument list is present
First attempt at tests for DUMP, starting with simple literals
Comment out debug output in DUMP routines in Mu.pm
Begin implementing indented DUMP output; Mu.pm changes only for first pass
Merge branch 'nom' into extend-dump
Merge pull request #119 from hoelzro/nom

More typo fixing
Reduce Mu.DUMP indentation levels and output length a bit