Talked to derwin about this.

Turns out this is the proper way to store an IP address because of ipv6,
I just had forgotten :(
Add support for RC file override

It still defaults to ~/.pasttlerc, but you can now override it with
environment variables, namely, PASTTLERC
Better do this now before more installs are found.

Apologies if this is crapping on everyone's cheerios :(