so that '_<flavor-name>' is appended to each built library, .e.g.
libhdf5_<flavor-name>.so.
This we can avoid library name collisions when installing both serial
and $mpi flavors of the libraries:
* serial is built with no flavor name
* $mpi parallel versions use --with-flavor=$mpi
===================================================================
Gbp-Pq: Name flavor-configure-option.patch