add mathematica-9.0.1
Build numpy against openblas
Don't set a default version of Mathematica

Nixpkgs should not set a default version of Mathematica. Many users of
Mathematica have institutional licenses and do not have immediate access
to new versions. If there is a default version in Nixpkgs, updating that
version will cause trouble for all such users.
Merge branch 'mathematica' into installed-next