ITS#2512 wrong order of entries in replog file

[hyc@highlandsun.com]

There is a partial fix for this now in CVS HEAD. The replog entries are now
timestamped according to when the operation began, instead of when the
operation was logged. The entries are still written in an unpredictable
order, but it is now feasible for the replog to be sorted into correct order.

slurpd has been modified to attempt to sort its queue when it reads the
replog. With this patch, if operations execute at close to the same time and
are logged at close to the same time, slurpd will replicate them correctly.
However, when the log is out of order, there is no check for missing
operations in a sequence. An operation that is significantly delayed (due to
database contention) may still be replicated out of order if it is not logged
by the time slurpd reads the replog. I.e., if all changes have been written
to the replog, then slurpd will send them all in correct order. If any
changes are outstanding/missing when slurpd reads the log, then the order is
not guaranteed.

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support