ECPG changes

I'm just committing the first changes to ECPGs parser so variables are
allowed wherever possible instead of constants. I'm pretty sure this breaks
stuff at one point or the other. Also I have not yet fixed all problems I
know about. So please bear with me.

I'd like everyone who has embedded SQL sources to test them with this
release and send me all bugs they can find, so I can create a roadmap for
7.1. I want to get this as bug free as possible.

Michael
--
Michael Meskes
Michael@Fam-Meskes.De
Go SF 49ers! Go Rhein Fire!
Use Debian GNU/Linux! Use PostgreSQL!