After fighting with all the signals and things that I had to rename, it looks like it is trying to synthesise, and in a couple of hours I will know whether there are more errors to deal with.
I had thought about implementing my own DDR memory controller, but it all looks a bit too much like magic from my initial look. I may yet change my mind if I have too much trouble building with it.
The big problem for now is that there are silly "all rights reserved" messages in some of the files, which seems rather at odds with it being "sample code" designed to make ones life easier. I will try to poke Digilent to see if they will update the copyright notices to better reflect the intended purpose of the code. In the interim, I guess I will just update the make file so that if given the zipped up demo project, it can extract the files it needs.
Hopefully it won't take too much longer to get the DDR memory working, and we can get back to more fun posts with screen-shots.