Removed:
- Removed all the synchronized dwell time code from the VESPERS
application.

Currently there is still a small issue where I need a new master dwell
time because although I would love to use the scaler, it is a factor of
1000 too large due to being in milliseconds.  Will need to figure out a
solution for that.
Removed:
- All instances of the CLS synchronized dwell time have been removed
from the VESPERS app.  It was causing bugs on startup where dwell times
would not propogate to the detector.
- In order to still have a dwell time PV, I created a new detector type
that is called AMScalerTimeControlDetector that encapuslates what is
expected to be the scaler time control and divides the value by 1000 to
be in seconds rather than milliseconds.
Merge pull request #921 from acquaman/Issue915

This looks good to me in terms of code. Changes outside of VESPERS classes seem very minor.