We can't "break symlinks after extracting tarball" because they populate
that dir during the build now. So instead cripple mklink.pl to
copy instead of link. (Configure no-symlinks simply skips the symlink
step instead of copying, so that appears useless)

Change-Id: Ib30b2c1b8b3de72511d09c478297a7a5a4bc691e
Reviewed-on: https://gerrit.libreoffice.org/21880Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>