Remove unused imports
Spelling
Bring ShoeAgent in line with improvements to the agent api
Add CRADLESTATE command
Caught a case which could admit response to the GUI not including ERROR
Rework fibershoe.ino and shoeAgent.

Add CS (connect shoe) command to bring shoe online. Support a subset of
commands when the locking nut is not engaged. Update versions. Improve
documentation and formatting. fibershoe.ino still needs documentation
work.