Change PV name string to match the official naming scheme
Added a calculation function to pull beam monitor counts from the
workspace sample log.
Make PV's update automatically

Add the 'scan' field to the pvdb dictionary so that PV values will
update without needing to be polled by something like caget.
New calculation function for beam monitor counts

Added a new calculation function to get the beam monitor counts from the
chunk workspace (which means we need to do the accumulation manually).
Changed to original beam monitor function respond to pv names with the
suffix _POST.  Also a few comment cleanups.