Implemented the spin.renumber() user function.
Implemented the spin.rename() user function.
Implemented the spin.display() user function.
Reordered the user functions in prompt/molecule.py.
Implemented the spin.delete() user function.
Implemented the spin.create() user function.
Implemented the spin.copy() user function.
Removed a few unused imported functions.
A few comment fixes.
Removed the unused and useless generic_fns.molecule.renumber() function.