Feature/caddy frontend improvement 202010

• simplify the profiles
  • merge common.cfg and development.cfg into software.cfg
  • improve parameters passed from instance.cfg.in
  • improve parameters passed from instance-apache-frontend.cfg.in
  • review passed parameters and minimise them
  • group parameters
  • instance-apache-frontend.cfg.in
    • expose software_parameter_dict instead of passing each binary separately
    • drop httpd_home and httpd_mod_ssl_cache_directory with backreferences (like caddy-location)
  • instance-apache-replicate.cfg.in
    • switch to nginx in rejected-slave-publish
  • instance-kedifa.cfg.in
    • switch to nginx in expose-csr_id
• test https://lab.nexedi.com/nexedi/slapos/merge_requests/836/diffs?commit_id=1175dcc0afbc60be848efb4a41a4210125e69001