[AppStream] AppStream 0.9.7 released!

[Matthias Klumpp]

Hello all!
This is a pretty massive release with lots of changes, please test it
and especially report performance regressions.
Since this release, a Xapian database is no longer necessary and you
can drop the dependency on Xapian.

There is already a big amount of changes and spec updates queued up,
so you can expect the next release to happen faster.

As always, tarballs are available here:
http://www.freedesktop.org/software/appstream/releases

Version 0.9.7
~~~~~~~~~~~~~~
Released: 2016-07-20

Notes:
 * This release contains a lot of very invasive changes and deprecates
some API, most
   notably AsDatabase. Please test this release carefully.
   There will be an API/ABI break in a future release, so if possible
please adjust your
   code to not use deprecated interfaces.

Features:
 * Don't fall back to Debian screenshots server if none is specified
for the distro (Matthias Klumpp)
 * Split out distro-specific helpers (Matthias Klumpp)
 * Implement Xapian-less search (Matthias Klumpp)
 * Use a pure PB cache instead of Xapian (Matthias Klumpp)
 * qt: Don't rely on Xapian for searches (Matthias Klumpp)
 * Deprecate AsDatabase (Matthias Klumpp)
 * Hide internal symbols from the symbols table (Matthias Klumpp)
 * Allow injecting components into the pool and unittest the cache
(Matthias Klumpp)
 * Add by-category filter to AsDataPool (Matthias Klumpp)
 * Validate Freedesktop category names (Matthias Klumpp)
 * Allow building AppStream with stemming support (Matthias Klumpp)
 * Cache search tokens (Matthias Klumpp)

Specification:
 * docs/quickstart: Clarify the role of releases/provides (Matthias Klumpp)
 * docs/quickstart: Screenshot images don't need to define
width/height (Matthias Klumpp)

Bugfixes:
 * qt: Properly expose enums for introspection (Aleix Pol)
 * qt: Make it possible to easily output data types using QDebug (Aleix Pol)
 * xml: Fix formatting of <screenshot/> tag (Matthias Klumpp)
 * xml: Work around non-threadsafe behavior of libxml2 (Matthias Klumpp)
 * xml: Properly write provides tag (Matthias Klumpp)
 * Fix code documentation for as_component_get_id (Lucas Moura)
 * Fix some xmldata methods documentation (Lucas Moura)
 * cli: Create metainfo directory if it is missing and respect DESTDIR
(Matthias Klumpp)

Kind regards,
    Matthias Klumpp