Added a second buffer to queue scan data from the next scan.

When connecting LMS100 over a wireless link, very soon after the laser
started to scan, LMS100 node would stop publishing scans and hog the cpu.
It turned out that sometimes the read from socket would read into the
middle of the next scan message, thus making (buf[len - 1] != 0x03).
Implemented setIP and reboot commands.
Removed some debugging printouts.
Implemented setTime command.

Also, doing round trip time estimation with a simple exponentially-
weighted moving average filter.
Getting timestamped scans.
Merge branch 'master' of https://github.com/jksrecko/libLMS1xx