pkgsrc/smartos packgin

Hi,
so this is a rather big pull request but I hope it's bundled up enough to still make sense. The goal is to add packages or SmartOS (or pkgsrc on SmartOS).

There is one change to the original code but only in the makefile adding the 'pkgsrc' target and adjusting 'clean' to also clean the pkgsrc code.

It should also build for other pkgsrc targets from the pkgsrc package but the path encoded there are optimised to be canonical in SmartOS (aka data goes to /var/db, files are in /opt/local and logs in /var/log).