The Mooney-Rivlin model and mlabpack.f files needed lapack installed
to build.  This commit adds a new file 'blas_lapack-lite' that
contains all of the lapack/blas fortran procedures needed to build
each.  If a model requires it built, it is compiled to an object
and then linked in by f2py when needed - this way it need only be
built once for shared object libraries that need it (it takes some
time to build).