[AppStream] appstream-glib 0.5.16

[Richard Hughes]

New Features:
 - Add elementary to list of project groups (Fabio Valentini)
 - Allow setting the id prefix and origin using a symlink name (Richard Hughes)

Bugfixes:
 - Add yast2-branding-openSUSE if an app depends on yast2 (Dominique
Leuenberger)
 - Correctly detect new AppStream apps in new directories (Richard Hughes)
 - Do not rename a category ID in AsApp (Richard Hughes)
 - Fix g_ptr_array_sort use (Kalev Lember)
 - Load metainfo files if present (Richard Hughes)
 - Never allow NULL to be added to AsApp string array (Richard Hughes)

Richard.