The basic idea of our configure script is to probe for things
rather than have them enabled by default. This is even more
visible in the next commit where configure fails if qemu driver
is enabled but no yajl is found.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJiri Denemark <jdenemar@redhat.com>