Change status from Planning to Pre-Alpha
Parse command object from command string
Parse command object with arguments
Refactor class names, remove GTP reference

The idea is that the connection to GTP should be evident from the GTP
module rather than from the class name, which would be repetitive.
Parse command object with identity number
Test for command with identity number and args
Test for command with several arguments
Parse command object with id and several args
Specify command string syntax from GTP specs

[ci skip]
Preprocess command string when parsing command
Reduce code contained within try-block
Refactor test to not instantiate for class method
Use a file-like object for GTP engine input
Use a file-like object for GTP engine output
Parse line into parts rather than command object
Add: standard error message for unknown commands
Add: protocol_version command
Include identity number with command response
Add: name command
Reuse test code to send command then get response