Added psync(port sync), updated puni, puo

Added psync(port sync) to performs a sync operation only on the ports tree of a MacPorts installation, pulling in the latest revision available of the Portfiles from the MacPorts rsync server.
Added -u option to puni,puo so that it uninstall non-active ports when upgrading and uninstalling.
-u to uninstall nonactive ports see this difference,

[~ZSH/plugins]$ puni                                                                                                                        [master][ruby-2.1.1]
Error: No ports matched the given expression

[~ZSH/plugins]$ sudo port -u uninstall inactive                                                                                             [master][ruby-2.1.1]
[~ZSH/plugins]$