relax SVN archive

Wrote the model_statistics() method.

Bug fixes and expansion of the __linear_constraints() method.

The bug fix is that the b array was not being scaled! This is essential when diagonal scaling is
active.

The added feature is that the pN weight of state N, which is not a parameter of the model, is now
constrained to be between 0 and 1. This is because the value is equal to 1 minus the sum of all
other probabilities, hence linear constraints can be created.

Added the ability to reload alignment tensors from the XML results file into the relax data store.

Ported r7099, r7100, r7101, r7103 and r7104 to the consistency tests code.

Fix for the test_display_argfail_tensor() unit test.

Loosened some unit tests for the alignment tensor.

Modified the alignment tensor objects.

These are now storing everything as alignment tensor parameters rather than Saupe order matrix
components and hence all the updating functions have been modified to match.

Modified the unit tests of the alignment tensor objects to use Axx rather than Sxx, etc.

Updated the set() function to set the alignment tensor parameters rather than Saupe order matrix.

Changed the list of modifiable alignment tensor objects.

Alignment tensor parameters rather than Saupe order matrix elements can now be changed.