driver: add explicit socket close on ABORT. Fix #27.

This change lets the state and trajectory relay components installs
an ABORT condition handler that will trap ABORT signals, and signal
to the respective applications that the user has requested the
programs to stop.

The handler will allow both programs to properly close the file
descriptor opened on the TCP socket, thereby properly shutting down
the socket connection itself.
m10ia: add info on specific config used for urdf/xacro. For #26.
lrmate200ic: add info on specific config used for urdf/xacro. For #26.
Experiment with KAREL motion interface.

Small test with the (deprecated) KAREL MOVETO and related instructions. By
specifying a SEG_TIME we let the controller approximate ROS-I command
velocity for the current trajectory segment.

TODO: test performance objectively.
TODO: do this with TPE.