Commits on Jan 16, 2017

1. Provide an error message as warning output …

   As discussed in the issue ximion#97, there's some systems where appstream is
   reporting that it doesn't load properly but the users on the platform
   don't have information on how to fix it.
   Provide a warning for frontends to display, giving indications on what's
   the problem.

   

   aleixpol committed Jan 16, 2017
   8f0241d