SERVER-10325: support system and user flags for mongos collstats
SERVER-13429 Use logging system in mongod signal handlers, test exit logging.

Still not really safe for signal handlers, but no worse than before,
and correctly logs to the log file/syslog, so an improvement.
SERVER-13438 Handle syslog case of systemLog.destination properly
SERVER-13379 Fixing parsed naming of jsonp option in mongos