added failed events for to count problem_events list returned from record_events
added write_concern and sharding to command line options
added defaults for journaling and sharding
removed sharding setting from test_setup.py
added write concern for mongo to command line
moved len call out of timing
default write concern of 1
default write concern of 1, cleanup
Merge pull request #16 from TMaddox/write_concern

Write concern and failed store handling