relax SVN archive

Removed a PDB reference in the __init__ docstring of the structural API base class.

Renamed a call to load_structures() to load_pdb().

Updated the Scientific python PDB structural object unit tests to call load_pdb().

Renamed load_structures() to load_pdb() in the Scientific python PDB structural object.

Changed a few method names in the API base class.

load_structures() is now load_pdb() and write_pdb_file() is now write_pdb().

Modified the unit tests to call Internal.load_pdb().

Updated the internal relax structural object unit tests to test this object.

Copied the Scientific python unit tests for the internal relax structural object unit tests.

Import fixes for the newly renamed generic_fns.structure.internal() module.

Module rename.