Bring in some fixes from the Debian package.

- pygeode.formats.fstd was not properly packaged.
- Extra .so files were being erroneously included in the package.
- numpy.distutils breaks down in debuild.  Revert to builtin distutils, and do
  the Fortran compilation in a separate step in the Makefile.
Release 0.8.1.
Fix bug in FSTD_Var.__init__, where the levels were being ordered incorrectly.
Release 0.8.2.