v1.5.0.rc3

• Improve transaction speeds for sync clients (RTU/ASCII), now retry on empty happens only when retry_on_empty kwarg is passed to client during intialization

client = Client(..., retry_on_empty=True)

• Fix tcp servers (sync/async) not processing requests with transaction id > 255
• Introduce new api to check if the received response is an error or not (response.isError())
• Move timing logic to framers so that irrespective of client, correct timing logics are followed.
• Move framers from transaction.py to respective modules
• Fix modbus payload builder and decoder
• Async servers can now have an option to defer reactor.run() when using Start<Tcp/Serial/Udo>Server(...,defer_reactor_run=True)
• Fix UDP client issue while handling MEI messages (ReadDeviceInformationRequest)
• Add expected response lengths for WriteMultipleCoilRequest and WriteMultipleRegisterRequest
• Fix _rtu_byte_count_pos for GetCommEventLogResponse
• Add support for repeated MEI device information Object IDs
• Fix struct errors while decoding stray response
• Modbus read retries works only when empty/no message is received
• Change test runner from nosetest to pytest
• Fix Misc examples