- removed ev3devcontext library; on pc use ev3dev api from simulator, on ev3
use the official ev3dev api.
- If you import the ev3devrpyc library then we can still use remote steering mode.
- improved ev3devcmd which only uses paramiko and is not dependent on rpyc anymore
- improved ev3devcmd uses sftpclone to mirror a whole source directory to ev3
- mirror removes files/dirs on target which are not in source directory
- mirror excludes files and directories in the rootdir which names start with a '.'
they are excluded both from mirroring as from deletion (if only at target,
but not in sourcedir)