This tests the interaction between mimeinfo.cache, defaults.list and mimeapps.list to ensure g_app_info_set_as_last_used_for_type doesn't incorrectly change the default. https://bugzilla.gnome.org/show_bug.cgi?id=658188
This adds a test involving both defaults.list and mimeapps.list.
In addition to looking at mimeapps.list, check that the default and recommended apps returned by g_app_info api are as expected.
These tests directly look at mimeapps.list to verify that we make the expected changes to the database.
