relax SVN archive

Converted the skip_function() method to the new relax design.

Fix for the call to the model_selection user function.

Converted all 0 and 1 flags to the bools False and True.

Fixes for the args of the model_selection() method.

The heteronucleus and proton types are now set.

Merged the SEQUENCE and SEQ_ARGS user variables.

Added access to all args of relax_data.read() through the RELAX_DATA user variable.

Converted all the force flags to bools.

Added the ability to change the sequence.read() arguments through user variables.

Removed a call to the non-existent nuclei() user function.