Bits of code that are effectively deprecated

[Whyborn]

Trying to compile a list of bits of code that seem to be completely redundant.

• cable_namelist_input.F90: code that inspects the command line args passed to the cable call. AFAIK, cable.nml is used universally, so the ability to read CLI args is entirely redundant. This file and calls to get_namelist_file_name should be removed altogether.
• This also means these lines are also redundant and should be removed.