This module defines a common timing API for all SLAC timing modules.

The objective is to be able to write timing service clients that work w/ the various
versions of timing modules that we need to support for LCLS-I and LCLS-II at SLAC.

Currently that includes these modules:
	event
	event2
	evrClient
	tpr

Of these, tpr is the only module to be reworked to support this timing API as of
initial introduction, Nov 17, 2017.

Key services provided by the timingApi include BSA callbacks and access to the
eventCode timing info including epicsTimeStamp, 64bit fiducial pulseId, cpu tsc
grabbed at ISR time, and a FIFO of these arrival times to support timestamp synchronization
modules including timesync and timeStampFifo.

Clients such as swBsa, timesync, timeStampFifo, ADUtil, and others that require
timing services would depend on this timingApi module, but could link w/ any
timing module that supports this timingApi.

Each timing module should use unique names for it's library objects so we can
create IOC's w/ multiple apps, one for each timing module.