Allow for initial delay (via a settable property) on buffered counter output.

[John_P1]

When using a buffered counter output task, the initial delay value is not used at all.  Instead, the user specifies an array of high and low times and the first low time is used as the initial delay.

If the output pulse train is repeated multiple times (or continuously), the first low time represents both the time from the trigger until the first pulse as well as the time between the last pulse and the first pulse.

It would be desirable to decouple these parameters by allowing for the option to use Initial Delay on buffered counter output tasks (e.g. with a channel property).  Here are a couple use cases off the top of my head where Initial Delay would be very helpful (if not required):

1.  This is the case I ran into (posted here😞  if you want to repeat a pulse train continuously every N seconds, you have to either have that N second delay at the start of the task or use another counter as a trigger source.  Depending on high and low times you might be able to get away with writing new values to the counter on-the-fly but this isn't a universal solution.

2.  If you wanted to synchronize multiple continuous buffered counter output tasks (with each one sharing a fixed desired period) to a common trigger source but with a different initial delay, you would be unable to do so since the requirement of having different initial delay would affect the period of your actual signal.  You would have to compensate by tweaking the other high/low times in your waveform (giving you something that you don't really want).