This is just a first draft.

The idea is if you are thinking of packaging something for current, you can see what
else needs packaging first, based on the dependency info in the stable
repo. 

The script assumes that pkgtxt2db (available from the repos) has been
run in the same directory to create CSV databases corresponding to both
Salix and Slackware current and stable/13.37

TODO:

Handle unexpected situations, such as if a Salix package is then
packaged upstream

Add 64 bit repos

Deal with alternative dependencies dep1|dep2

Organise the output better

Rewrite it to make it a lot more efficient and elegant