Log Message:
Update to 3.1.1

* Update MASTER_SITES and HOMEPAGE.
* set LICENSE
* Fix pg-config --cflags output

Changelog:
3.1.1 (2010.2.3)

        A bug in data encoder has been fixed.

3.1.0 (2009.6.6)

        Various code cleanups and performance improves.
        Strict internal error checks have been added.
        "--without-tests" has become default setting. Specify \ 
"--with-tests" to compile test programs.
        Some memory leak bugs have been fixed.