Improved daemon features

Send sigterm
Use PID lockfile
Refactor
Bump up queue size to avoid overflows under typical conditions
Added signal handlers; disabled; crashy

When I enabled these signal handlers, established a connection to the
DataServer, and sent SIGTERM, Python crashed hard, some sort of glibc
memory corruption. I don't really have time to debug this. In the future
somebody might want to:
* Try on another machine
* Try with another version of greenlet
* Another version of gevent
* Run on a debug build of python/gevent/greenlet
* It could also be Antelope's fault for all I know; develop a test case
  that doesn't use antelop.

Anyway all the signal handlers do is facilitate a graceful shutdown, not
super critical considering what the port agent does; a quick stop is
acceptable IMO.
Fixed up remote cmds & made tiny cmd client
Fixed orbreapthr/get race

The cause of the on-exit crashes was the get call being issued after the
orbreapthr had been destroyed, or destroyed the orbreapthr when get was
blocked. Fixed the race, fixed the crashes.

Turned signal handling back on for graceful shutdowns.