speed improvements.
Penlift stuff.
Create README.md
Fix for bad coordinates in direct move.
Removed a couple of changespeed commands, added feature to persist speed instead.  Fixed loading speed from eeprom, that was a weird bug with float comparisons.
Merge branch 'background-comms' of https://github.com/euphy/polargraph_server_polarshield into background-comms
Merge pull request #1 from euphy/background-comms

Background comms