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