phases: emit phases to pushkey protocol in deterministic order An upcoming test will report exact bytes sent over the wire protocol. Without this change, the ordering of phases listkey data is non-deterministic.

keepalive: send HTTP request headers in a deterministic order An upcoming patch will add low-level testing of the bytes being sent over the wire. As part of developing that test, I discovered that the order of headers in HTTP requests wasn't deterministic. This patch makes the order deterministic to make things easier to test.

revset: properly parse "descend" argument of followlines() We parse "descend" symbol as a Boolean using getboolean (prior extraction by getargsdict already checked that it is a symbol). In tests, check for error cases and vary Boolean values here and there.