lnpeer: birth of peer package!
lnpeer: birth of peer package!

This commit moves the generic interface for
Lightning Network peers so that it can be
imported directly into the switch and gossiper.
Eventually, the majority of the peer logic
would be moved into this package for testing
and modularization.

LightningNetwork/lnd,aakselrod/lnd,LightningNetwork/lnd,aakselrod/lnd