CSO - CAMS Satellite Operator

See "History" chapter in documentation for changes.

Added ``--single`` flag to run script to allow running just one job step.
  py/utopya_runscript.py
  py/utopya_jobtree.py
  bin/cso

Improved code that is added to job script to load Environment Module functions.
  py/utopya_jobtree.py

Print warning on missing `tasks` list.
  py/utopya_jobtree.py


Introduced `config` directories to store settings.
  config/
  rc/

Support ESA `PAL` archive.
  py/cso_pal.py

Introduced tools to inquire S5p archives. 
  py/cso_inquire.py
  py/cso_scihub.py
  py/cso.py