relax SVN archive

Removed the creation of the model selection data pipe, as this is now automatic.

Removed the check for the same sequence data in all pipes.

For flexibility, this check should not occur as some models are sequence independent. And the
checks weren't functional anyway.

Import fixes for the module.

Added a test to make sure that the model selection data pipe doesn't exist.

Removed an unused ancient variable.

Added a missing import.

Fix for the res_name arg unit test of the residue.create() user function.

Reverted the removal of the call to the specific duplicate_data() method.

Fix for the residue.create() user function. The residue name is not necessary.

Wrote a system test for the loading of NMRView peak lists.

This comes from Ryan Hoffman's (https://gna.org/users/rydog) feature request attached to bug #11913
(https://gna.org/bugs/index.php?11913).