Prior to this change, the button change events were only happening on
periodic intervals corresponding to the change in the mouse REL_X and
REL_Y values. However, this has the issue that it tends to miss a few
events, especially those related to the scroll wheel.
This change reports button and wheel events immediately when receiving
the report, but it leaves the motion to be updated by the thread.
Prior to this change, the build would fail on macOS systems because the
evdev sources were only included on Linux systems, and macOS does not
have evdev/libevdev. By separating out the configuration and update
threads, this should build on macOS, but the configuration would be
ignored.
This change adds the configuration and build related changes for
supporting the virtual mouse. Subsequent commits will add support for
reading the IO interface and translating it to mouse commands.
nirenjan