Code review comment for lp:~hopem/charm-helpers/fix-lp1425999

Hello Edward.

I found out that there is a few other places on which similar host<->ip logic
is being used. I just re-factored/moved this to the contrib.network.ip module, which
in my opinion is a better place for having this.

The proposal: https://code.launchpad.net/~niedbalski/charm-helpers/ip-host-translation/+merge/251189

I would suggest to review that and integrate your code according to the inline comment.