relax SVN archive

Loosened the checks in the angles calculation system test to allow 64 bit platforms to pass.

Converted the return_units() function to the new relax design.

Converted the return_conversion_factor() function to the new design.

Added the dummy spin_id keyword arg to the map_bounds() function.

Reverted r5933, as this change was incorrect.

The command used was:
svn merge -r5933:5932 .

Fixed the call to map_bounds().

Updated the map_bounds() function to the new design.

Fix for the calls to the functions of the generic_fns.diffusion_tensor module.

Modified the read() function to write out all the new spins.

Fix for the test_opendx_theta_phi_da() system test.

The spin information is now loaded.