[pkg-go] Updated pkg-go post-receive hook

[Martín Ferrari]

Hi all,

I noticed that the PET page was seriously out of date. Tracing this
issue I found out that we are not calling the PET helper on post-commit,
as we should. So I have just updated the common script to do that and more.

Taking from the pkg-perl example, the new script will call KGB for IRC
notifications, call the PET helper so the PET page is always current,
and adds a nice feature that I loved from pkg-perl: when you commit a
change that closes a bug (indicated by a Closes: XXX stanza in the
changelog), it will automatically mark the bug as pending in the BTS.

If you see any issues with the new script, or if you feel strongly
against the new functionality, please let me know.

Tincho.

-- 
Martín Ferrari (Tincho)