Issue #1498 - Mongo -> MongoClient Transition

Deprecated MongoAddress, MongoHostBase, MongoHost, MongoSet, and the MongoDB functions that take them as an argument.

Deprecated the MongoDB functions that take Mongo as an argument and added ones that take MongoClient as an argument.

Deprecated MongoRecord.save (no arguments).

Added default argument of `true` to MongoRecord.save(safe: Boolean) function.

Added MongoRecord.save(inst: BaseRecord) function that uses the WriteConcern configured in Mongo/MongoClient.

Added saveBox(), updateBox(), and deleteBox_! functions to MongoRecord that all wrap the related functions in tryo and return a Box.

Internally, MongoDB still uses Mongo, so no behavior will change unless MongoClient (or MongoOptions with a different WriteConcern) is used.