Add test coverage for disabling a catalog due to version, and also
for auto-migrating to a new version. Expose disabled catalogs on the
Root, so they can be checked for.
- check the catalog version explicitly when refreshing
- handle packages with distinct dir name / primary ID correctly
(requires an updated catalog XML format)
- rename failure code to status code, and add more to handle
cancellation.
- change caching of active Installs from Catalog to Root, to clarify
ownership
- expose download status on Install
- adjust Delegate signatures to pass more information
Basic library infrastructure, catalog download/refresh, and package install,
uninstall and update. Disabled at cmake time by default, and not yet hooked
into FlightGear.