Add some documentation about signature argument to pirop_mapper.
Store REPR data offset in STables data also.

This makes it much easier for anything that wants to try and work out
sizing/layout before deserializing objects.
Add nqp::x_posixerrno
Add test for nqp::x_posixerrno and pir::const::POSIX_*
Add script to generate list of errno value macros
Generate nqp_const.pir as dependency for building NQP
Include nqp_const.pir in registered constants
Ignore generated nqp_const.pir file
Merge pull request #86 from hoelzro/master

Expose errno and POSIX errno values to NQP
Install nqp_const.pir.
[docs/release_guide.pod] formatting fix
bump VERSION to 2013.03
[docs/release_guide.pod] fix upload instructions
when encountering an error during compilation, show the source text if available
Bump PARROT_REVISION for Socket fixes
Add arnsholt++ nqp::sethllconfig implementation.

Also teach it a bunch of extra HLL-interop related keys.
Start of new HLL-interop infrastructure.

Builds upon the Parrot HLL identifiers. This mechanism will be used to
fix various Rakudo issues when NQP-defiend objects are encountered. It
will also replace the special-case perl6ize_type with a more general
and more portable mechanism, that can work in an environment where all
objects are 6model objects.
Code object mapping support.
Interop mapping support for 6model objects.
Make nqp::setcodeobj cool with coroutines.