aliases for git.

pu is pretty simple.  Merge the upstream you forked from into
your branch.

db is helpful when you have tagged commits when you deploy, and
want to see what branch(es) contain the latest tag. So if you tag
your commits production_YYYY_DD_MM_HH_MM, for instance, you can
do git db procution and it will find the latest tag, get the sha
from it, and see what branches (on the remote too) have this sha.

It uses lastsha and lasttag, both take that same regex (producton,
or whatever).