CDRIVER-442 reimplement mongoc_database_has_collection using mongoc_database_get_collection_info
CDRIVER-415 Add documentation to deprecate dropDups

Closes #105
CDRIVER-404 Implement SCRAM-SHA-1 SASL Mechanism

Implements Scram Sha1 for the c driver
CDRIVER-429 Bump maxWireProtocolVersion

Closes #107
CDRIVER-427 move header include guard above checks