All driver use statements should be to marbl_interface*

[mnlevy1981]

The stand-alone driver currently requires the following from libmarbl.a

  use marbl_interface,    only : marbl_interface_class
  use marbl_logging,      only : marbl_log_type
  use marbl_logging,      only : marbl_status_log_entry_type
  use marbl_namelist_mod, only : marbl_nl_in_size
  use marbl_namelist_mod, only : marbl_nl_cnt
  use marbl_namelist_mod, only : marbl_nl_buffer_size
  use marbl_namelist_mod, only : marbl_nl_split_string
  use marbl_namelist_mod, only : marbl_namelist

and

  use marbl_kinds_mod,     only : r8
  use marbl_constants_mod, only : c1, p5

I think we want all these variables to come via marbl_interface / marbl_interface_types (and maybe the last two via marbl_interface_constants). The easiest solution would be to leave them where they are, but add use statements in marbl_interface*.F90 and make the above variables public in that module.