make **@ available for multi subs.
Implement the whole list of valid adverb combinations from S02:2533
Need to revert xor logic to be correct
Booleanify ?^, as discussed with Pm

As shown at http://irclog.perlgeek.de/perl6/2013-06-07#i_7170609
Added support for :exists with :kv:p:k
Implement :$<foo> colonpair syntax.
:exists? :k doesn't make sense, remove it.
Normalize candidate order for better readability
Fix LTA error on 'my &foo; multi foo() { }'.
Start checking reduce for fiddliness.
Eliminate a now-unrequired hack.

This as a side-effect fixes RT#111734.
Change quoting to capture the version correctly under Windows.

Windows Command.exe does not understand single quoted parameters so perl6 -v returned no version number.
first should return Nil on not found.

RT #118141
Fix self-inheritance detection.
Merge pull request #162 from thundergnat/patch-1

Change quoting to capture the version correctly under Windows.
NaN.Rat -> NaN

RT #77820
Make {}:kv {}:p {}:k {}:v behave according to spec
Some shifting in candidate order to make searching easier
Make sure that [*]:(kv|p|k) pass on their values
Simplify {*}:(kv|p|k|v) to self.(kv|pairs|keys|values)

as the value specified doesn't really matter in this case, and it is the same
as the zen-slice logic.