Support global catalog and fix issue #66

With this PR all global catalogs are accessible by vagrant-vcloud even if they aren't listed in the /api/org/org_id request.

If function `get_catalog_id_by_name` couldn't find the catalog in the org catalog list, then it does an HTTP request `/api/catalogs/query/` and searches for catalogs there.

I haven't tested it with the upload feature. But creating vApps (that's the normal use case for read-only global catalogs) is now possible.