Improved process_headers.pl and fixed newly-found include weirdness in s2.
Fixed process_timings_output.pl.
Merge branch 'sam_process_headers_improvement' into next
Implemented full mixed number support.
Merge branch 'sam_process_timings_improvement' into next
Merge branch 'next' into sam_timestamps_with_a_vengeance
Got rid of transition_timestamp_t::to_repli_timestamp.  Made callers change behavior, calling timestamp_after.

Probably a bugfix if not an introduction of a bug.