- Trim and ensure neutrality of descriptions.

- Update License to "LGPL-2.1+ AND GPL-2.0+": the client tools
(builder, compose and util) are licenses GPL-2.0+, the library
is LGPL-2.1+.

- Update to version 0.7.2:
+ Allow remote icon types for desktop AppData files.
+ Do not check the suffix of tags.
+ Prefer /usr/share/metainfo as default path for metainfo files.
+ build: Enable C99 support in meson.build.
+ build: Define _XOPEN_SOURCE in order to expose realpath() in
headers.
+ libappstream-glib: Use g_ascii_strcasecmp() instead of
strcasecmp().
+ libappstream-builder/utils: Drop an unreachable branch.
+ libappstream-glib/self-test: Add some additional checks.

- Update to version 0.7.1:
+ Validate the format according to the spec.
+ Add kinds for application provides.
+ Skip loading desktop data from Snap directory.
+ Update the SPDX license list to 2.6.
+ Support CompulsoryForDesktops in YAML.
+ Have plugins link with asglib along with asbuilder.
+ meson: avoid unnecessary gdk dependency.
+ meson: introspection optional.
+ meson: Install appdata-xml.m4.
+ build: Make gperf dependency fully required.
+ Fail to validate if AppData screenshots are duplicated.