+JH/16 Bug 2615: Fix pause during message reception, on systems that have been
+ suspended/resumed. The Linux CLOCK_MONOTONIC does not account for time
+ spent suspended, ignoring the Posix definition. Previously we assumed
+ it did and a constant offset from real time could be used as a correction.
+ Change to using the same clock source for the start-of-message and the
+ post-message next-tick-wait. Also change to using CLOCK_BOOTTIME if it
+ exists, just to get a clock slightly more aligned to reality.
+