Galil and DAE continuous scanning timestamp modifications

To allow a pure software scanning test for comparison with later tests of feeding isis TOF pulse into galil:

Adjust time stamping of motor position in the galil IOC as follows:

- create a time baseline and use the Galil Tick counter (plus number of wraps) to provide an absolute motor time
- propagate this timestamp up from the driver to the EPICS channel access layer
- for information purposes, keep track of difference between epics time and galil time to see how it drifts

DAE control program time

Both EPICS and the ISISICP DAE control program use the windows high performance timer, but EPICS gradually adjusts its high performance reference to match PC time where the ISISICP only does this at specific points (like a begin). They need to use the same reference.