trace now shows memory accesses
pass args to sim
pass args to sim
decode numeric display value as a double
move register tracing routines
make conditional on HPIB_SIM
make bus clock first to change
move register tracing routines
add microsecond timer routine
new active high/low mechanism

Added a new mechanism that attempts to deal more easily with the 5370
register bits/signals that are active high vs low. Cure might be worse
than the disease however..
hpib_fast_binary_init() now bus_gpio_init()
hpib_fast_binary_init() renamed bus_gpio_init()
process args in sim_init() now
use PRU to solve real-time issues

Use the PRU (programmable real-time unit) of the processor chip to run
the N0/N3 register overflow counting code and generate the 5370 bus
cycles.