Lower typical proto-method signature.

Was missed in the first pass, and is very common.
Fix warning; diakopter++.
Lower signatures containing coercions.
More optimal Enum($val) implementation.
fix IO::Path.contents for moar
Lower slurpy array and some capture binds.
Get NQP with improvements/fixes.
Fix various closure-related issues.

In these places we wrongly fell back on auto-close, which is slow and
wrong.
Get NQP with JVM/Moar continuation improvements.
Fix GatherIter not to add a frame every take.

Fixes the typical case of StackOverflowException on the JVM, and leads
to far better gather/take performance on both MoarVM and JVM.
Micro-optimize GatherIter.
Some more ChangeLog entries.
prepend path in dir() when needed
Fix braino.
bump nqp/moar rev to get unicode fixes
Fix build on OS X

OS X's linker seems to be more strict than Linux's and requires you
actually tell it to link against the moar library.  Re-use the
previously Windows specific @moarimplib@ to add that flag.
Ignore OS X shared libraries
Remove unneeded Windows tweak
Add DESTDIR to m-install
Add Setty.kv and Baggy.kv.

lue++ pointed out that calling these on Sets and Bags returned silly results,
so I implemented proper versions.