Make sure the CA is running when starting services
    
    - Provide a function for determinig the CA status using Dogtag 10's new
      getStatus endpoint.
      This must be done over HTTPS, but since our client certificate may not be set
      up yet, we need HTTPS without client authentication.
      Rather than copying from the existing http_request and https_request
      function, shared code is factored out to a common helper.
    - Call the new function when restarting the CA service. Since our Service
      can only be extended in platform-specific code, do this for Fedora only.
      Also, the status is only checked with Dogtag 10+.
    - When a restart call in cainstance failed, users were refered to the
      installation log, but no info was actually logged. Log the exception.
    
    https://fedorahosted.org/freeipa/ticket/3084