Changed vp->attribute to vp->da->attr, etc.

Also fixed a number of bugs left over from v2, where vp->attribute
was checked, but vp->vendor wasn't checked.

This commit may leak memory, crash, etc.  But the server builds
and seems to run.  It's one more stage on the way to the new API
Make the lib directory use vp->da
Make the main directory use vp->da