[Bizgres-general] Bizgres source enhancements, expected 0.9 release

[Luke Lonergan]

In the Bizgres source code on Bizgres CVS tip there are the following:

- On-disk bitmap index (Jie Zhang)
- Sort performance patch (Simon Riggs / Tom Lane)
- Copy extensions (Alon Goldshuv)

We'll be posting performance validation of the above as we move forward
toward an expected 0.9 binary release toward the end of March.

- Luke