Changed default from 0 to -1 as reading 0 bytes is a technical possibility
Started moving all terminator logic to the wrappers
Cleaned address property in Instrument
Updated sendcmd and query to reflect moving of terminator logic
Moved read-until-terminator logic downstream from GPIBWrapper
Moved appending terminator characters out of GPIBWrapper
Added SerialWrapper class
Changed serialmanager to use serialwrapper
Disabled setting address in serialwrapper since manager would break
Corrected import errors