replaced Mongo() with MongoClient(). fall back to Mongo() if not available.
added connection_opts config to pass down to MongoClient()/Mongo() usage for configuration if replicaSet via config instead of URI params
updated readme with replicaSet example
avoid defunct 'safe' mode and use write concern/journal config. 'safe' mode fallback for Mongo()
replaced locks->save with locks->insert and updated exception handler to properly fail on exceptions other than duplicate key, like write concern
detect replication time out and attempt unlock to avoid lockout
updated readme with acknowledge/journaling config details
updated dbInit with version detection to use createIndex instead of defunct ensureIndex. also added log entries on index creation.
replaced dup key regex with match on 11000 exception code
added additional potential exception codes for duplicate key
per nicks request - updated unlock() with an optional force parameter to use to force an unlock rather than simply flagging it locked
untabified content via emacs
simplified line 210 per nicks suggestion
Merge pull request #5 from rocksfrow/master

MongoClient() updates, lock race fix, write concern support