SerialHost is given default instance from either SerialBE or SerialLE
The choice between those two classes is made with CPP
SerialBE, -HE, and -Host combined into one class, likewise with GSerial-
 - Instances for Word and Int have failing fixed-endianness
   serialization functions
Merge pull request #10 from ekmett/SerialHost-with-default-sigs

SerialHost is given default instance from either SerialBE or SerialLE
Removed SerialEndian instances for Int and Word
Serial instances are kept