Here's a small patch to add the full suite of btree operators for tids and the
corresponding btree opclass. This came up a while back on -hackers and a few
people were interested in it at the time. I just had a need for it again so I
added it.
I'm not sure how to allocate OIDs. I just looked for the greatest one in the
various .h files and started from there. It leads to some strange
discontinuities since there were existing = and <> operators.
--
greg
