* bin/tame (TAME_CMD_WAITTIME): Renamed from `RUNNER_CMD_WAITTIME'.
Inherit from environment, default 3.
(command-runner): Sleep for an additional TAME_CMD_WAITTIME seconds after
requesting runner reload to give more time in case of high load.
(verify-runner-ack): Rename variable.
(usage): Document env var.
* build-aux/Makefile.am: Export TAME_CMD_WAITTIME.