fix initialization of PRU in auto-start mode

The PRU wasn't starting properly in auto-start mode when the BBB was
booted. Need to wait for /dev/uio to be created by driver after PRU
.dts loaded. Keep a copy of the PRU binary in /usr/local/bin with the
app.
add arg to show IP address and exit
need "./hd" instead of just "hd"

Installing on a new BBB requires invoking the app with "./hd" since the
"make install" hasn't yet installed a new ~/.profile that includes '.'
in the $PATH
add alias for 'journalctl'
new instruction tracing

Reworked instruction tracing debugging output to allow for some simple
data flow analysis.