RE: 7.2 items

> * Add ALTER TABLE ... DROP CONSTRAINT

I am working on this function at the moment, hoping to add the dropping of
CHECK constraints.  However, it'll take me a while because I keep having to
look up all the functions being called to see what they do, etc.

What I'm thinking it that I'll try and at least get the structure all done
and even compiling then the patch will have to be reviewed. (I'm doing it to
stretch my programming muscles after working in PHP for so long!)

Chris