v2.3

• Removed the necessity of gen_server calls for prepared statements. Observed this as being a bottleneck under heavy load.
• Removed from erlcass module all methods starting with uuid_* and date_from_epoch/1, time_from_epoch/1, date_time_to_epoch/2. Instead this functions you can use the one from erlcass_uuid and erlcass_time modules.
• Updated cpp-driver to 2.3.0
• Internal code refactoring