relax SVN archive

Shifted the maths_fns.rdc and maths_fns.pcs modules to lib.nmr.

This is part of the relax library redesign.

Shifted the maths_fns.alignment_tensor module to lib.nmr.alignment_tensor.

This is part of the relax library redesign.

Set up the unit testing infrastructure for the lib.nmr package.

Updated the lib package __all__ list.

Created the empty lib.nmr package of the relax library.

Renamed the maths_fns.rotation_matrix module to lib.geometry.rotations.

This is part of the relax library redesign.

Shifted the physical_constants module into the lib package.

This is part of the relax library redesign.

Renamed the ansi module to lib.ansi.

This is part of the relax library redesign.

Fix for the relax status object install_path variable.

This was using the 'relax_errors.py' file to determine the installation path, but this file no
longer exists.

Updated the test_suite.unit_tests package __all__ list.