Merge pull request #2668 in HDFFV/hdf5 from monotonic_timer to develop
* commit '7371c83f9777b34b31909e99e052398b93c31bed':
Remove non-existent example
Add new source files to CMake build
Clean up warnings
va_arg -> HDva_arg
Refactor code to remove remaining checks for H5_HAVE_GETTIMEOFDAY scattered around in various places. Also clean up iopipe.c.
Correct mistake in H5_now_usec calculation for clock_gettime.
Remove detection for mach/mach/time.h, since we're no longer using the time routines from that header.
Update H5_now_usec to prefer using clock_gettime.
Changes to make timers within the library monotonic.
