relax SVN archive

Created a generic_fns rdc module by copying the relax_data module.

Converted all of the rdc user functions from the relax_data code.

Converted all instances of 'relax_data' to 'rdc'.

Converted all instances of 'ri_label' to 'id'.

Converted the rdc.read() user function from the relax_data.read() code.

Removed some debugging code.

Fix for the return_data_name() method when no match occurs and the index flag is True.

Added a number of new parameters to the return_data_name() method.

This include the bond length, and heteronucleus and proton types.

Fix for the return_data_name() method when no match occurs and the index flag is True.

Switched from os.devnull to devnull from relax_io.open_write_file().