postgresql version detection severly broken

[rpyne at kinfolk.org]

The version detection in the postgresql module is severely broken. It 
looks for and exact match of the version.

I have version 8.3.3 installed and it refuses to allow installation 
of version 8.3.5.

I have worked around it by simply deleting the CONFIGURE file from 
the moonbase, but that shouldn't be necessary.

--Richard