Implemented `-c command'.
Implemented `-c command'.

Fixed bitrot (__dead went away; EOF is now wrong for the getopt failure
value).

Moved sleep command to the end of the main loop to avoid mismatch between
main loop and the report loop.  There is an extra iteration that could be
used to calibrate the loop overhead, but was used to report wrong results.

Fixed usage message.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase