ordered indexing for integers

[Howard Chu <hyc@symas.com>]

I was looking at adding support for ordered indexing for Integer attributes. 
This would be an incompatible format change for index databases. In fact I'd 
need to change the Presence index key as well, so it would affect all index 
databases, not just those for Integer attributes.

Currently the Presence index uses a hardcoded 4 byte key of 0x00000001. I want 
to change it to a 2 byte key of 0x0000 instead, to prevent it from colliding 
with the Integer key space.

So far, 2.4 and 2.3 have totally identical database formats. Is it worthwhile 
to break this compatibility to gain this feature, or better to preserve 
compatibility and ignore this feature for now? Any thoughts on going ahead 
with it here in RE24?
--
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP     http://www.openldap.org/project/