What's new in at-spi2-core 2.37.90:

* Add a mode-changed signal to allow a screen reader to indicate
 that its mode has changed.

* Fix use after free when a device listener is destroyed (#22).

* Meson: de-duplicate deps of 'Requires' in pkgconfig file (!28).

* FIx use after free when an event listener is destroyed.

* Make at-spi-dbus-bus.desktop validate (!30).

* atspi_accessible_set_cache_mask: relax assert that was generating a
 warning and causing the function to fail in some cases.

* Fixes for synthesizing keys.

* Fix Qt annotations in DBus xml files.

* Memory test: replace gedit with a light-weight test application.

* dbtest: print to stdout instead of stderr.

* Tests: make test a bit verbose.

* Constants: fix typos in two _COUNT constants.