clobber accept_config*.txt on each build
clobber accept_config*.txt on each build

Previously, we appended to these to allow separate compilation to merge the
configuration space. Now we process the whole program at once, so appending
was just getting in the way.

jck/accept,uwsampa/accept,uwsampa/accept,jck/accept,uwsampa/accept,jck/accept,jck/accept,uwsampa/accept