cml: Add support for CML <list>

This will be needed for the orbitals module.
wcml: Add output format for molecular orbitals

As used by NWChem
wcml: Add support for input dumper to take unit

This writes out the file opened as a unit number. Only
use this if you know what you are doing.
wcml: Don't let the user provide dec dictRef

The dictionary reference for input dec dumping
is fixed by the spec, so don't let the user change
it. Also, we need to make sure we are in 'compchem'
mode.