relax SVN archive

Change the import order.

Shifted the gyromagnetic ratio values into the physical_constants.py file.

Updated all the unit tests of the alignment tensor data structure.

Modified the generic_fns.align_tensor.set() function to handle the Saupe and prob matrix.

Big modifications to the alignment tensor data structure.

The Saupe order matrix elements are now defined and are the default. The Aij elements are now all
calculated from the Sij elements. The Pij elements are also now calculated.

Added sections to the init() function for the different tensor types.

Small docstring change.

Modified the align_tensor.init() docstring to include the Saupe order matrix, Prob matrix, etc.

Started to implement the generic_fns.align_tensor.singular_values() function.

Created the align_tensor.svd() user function to do SVD on the loaded tensors.