The generation process of application was sequentiel until now, since
some files were generated to a specific name and the renamed. Or in
case of i386 the grub_iso directory was shared. This dependencies were
removed. You can `build_and_test' both variants of coredos with -j<N>.

Change-Id: I705f4d7a23351f97d7b48e768e23ead127b87724