Changes to the pcs.read() and rdc.read() user function interfaces.
Columns are now numbered from 1 - note this will break many things! The spin_id_col is now accepted and the spin_id arg is explained.
The docstrings have also been modified all over these user function classes to replace 'identification string' with 'ID string'.
Authored by: bugman 2009-10-06
Parent: [r9569]
Child: [r9571]
