Add broctl option to change the starting Bro port

Addresses BIT-1117
Added ability to expire entries in stats.log

Added ability of broctl cron to expire entries in stats.log that are
older than the number of days specified in the new broctl option
StatsLogExpireInterval.
Add test for broctl cron expiring stats.log entries
Merge remote-tracking branch 'origin/master' into topic/dnthayer/ticket1117
Fix a typo and add a test of the BroPort broctl option
Merge remote-tracking branch 'origin/topic/dnthayer/ticket1117'

* origin/topic/dnthayer/ticket1117:
  Fix a typo and add a test of the BroPort broctl option
  Add broctl option to change the starting Bro port

BIT-1117 #merged
Merge remote-tracking branch 'origin/topic/dnthayer/ticket123'

* origin/topic/dnthayer/ticket123:
  Add test for broctl cron expiring stats.log entries
  Added ability to expire entries in stats.log

BIT-123 #merged