[AppStream] appstream-glib 0.5.17

[Richard Hughes]

Version 0.5.17
~~~~~~~~~~~~~~
Released: 2016-07-13

New Features:
 - Add AS_STATE_PURCHASABLE and AS_STATE_PURCHASING constants (Robert Ancell)
 - Add external (X-*) keys of an app's desktop file as metadata AsApp
(Joaquim Rocha)

Bugfixes:
 - Correct disabling of timestamps for gzip (StefanBruens)
 - Do not add multiple categories for apps with AudioVideo (Richard Hughes)
 - Do not emit a warning when flatpak user directory doesn't exist
(Kalev Lember)
 - Fall back to the country code in as_app_get_language() (Richard Hughes)
 - Fix gtk-doc build when builddir != srcdir (lantw44)
 - Optionally use libstemmer for keyword stemming (Richard Hughes)
 - Use non-deprecated glib API for monitoring renames (Kalev Lember)

Richard.