Currently, mongos_main.cpp does startup initialization for mongos and mongoq.

This ticket is to make a copy of mongos_main.cpp called mongoq_main.cpp and remove the parts that are not needed in mongoq, specifically:

• Updating the config server's config.shards on hearing changes to a replica set's membership (code)
• Refreshing the BalancerConfiguration (code)
• Initializing the ShardingUptimeReporter (code)