Python >= 3.2 fix for the Relax_disp.test_sod1wt_t25_to_sherekhan_input system test.
The B0 field value of the ShereKhan input files created by the relax_disp.sherekhan_input user
function was formatted as "%s". However in Python >= 3.2, floats are now converted to have 14
decimal places whereas previous Python versions only had 10 places. The user function backend now
forces only 10 decimal places to be written to the input files.
