AlwaysCore and SendCoreEvents specify whether a device is to send core
events. A device that has either disabled is not supposed to send core
events.
With MPX/XI2, a device that is attached automatically sends core events when
the event is routed through the master device. Floating a slave device
disables core events by breaking the route.
This patch automatically floats devices that have coreEvents disabled in the
xorg.conf/HAL. This replicates the behaviour of a SendCoreEvents "false"
device in server 1.6 and earlier.
The devices may still be reattached to a master at runtime.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>