Store pusher remote address and push protocol in PushLog
Summary: Ref T4195. Stores remote address and protocol in the logs, where possible.
Test Plan: Pushed some stuff, looked at the log, saw data.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T4195
Differential Revision: https://secure.phabricator.com/D7711