Not yet built tested, beware.

- Update to version 0.14.4 (needed by future Discover versions)
* qt: Expose setter and getter for pool cache location
* utils: Use GLib's gstring_replace if available
* its: Allow to mark release descriptions as non-translatable
* compose: Point people at the specification if metadata license is invalid
* docs: Clarify which metadata licenses are permitted
* docs: Fix a typo on the icon cache page
* spec: Add a paragraph about which license to put in
* Add documentation for YAML release type and urgency
* Add documentation for YAML provides
* component: Don't strip ";" from keywords before translating them
* utils: Don't strip modifiers when stripping encoding
* compose: Check optipng is there before we use it
* Improve text line wrapping, especially if many newlines are present
* Make word-wrap function unicode-aware
* Make license_is_metadata_license parse more complex expressions
* Improve cache refresh code, don't flag cache as updated if update failed
* Use system cache even if we had to drop some invalid metadata
* Assign more string class members safely
* Fix flashed firmware generating incorrect XML
* Fix YAML having wrong names for the firmware data (forwarded request 910733 from luca_b)