fixes #2411 - add autoload_paths in application.rb in preparation for file location changes
fixes #2411 - move files in /models to /concerns, /services, /mailers, /observers
fixes #2411 - move STI models in /models and /lib/foreman/models to sub-folders
move to controller/concerns
moved files to /app/services
move lib/audit_extensions lib/fog_extensions lib/foreman to models/concerns