Added Average Voltage measurement
Read LVDT voltage using oscilloscope average

Instead of reading the channel data and averaging in the PC
Fixed typo in voltage measurement command
test_positioner.py now saves axis, model and speed
repetibilidad.py measures positioner repeatability

It moves the positioner back and forth, measuring the dispersion of the
position measured at specific destinations along the axis.
Added 'run' command
Fixed average_signal
Fixed repeatability analysis

Instead of saving just the moments of the LVDT measurements for each
position, repetibilidad.py now saves all of the positioner and LVDT
measurements. analize_repeatability.py takes care of grouping the data
for analysis.
Fixed HP54616B.run()
Delay before measuring LVDT, fixed headers
Slightly cleaned up writing headers for run data