Merge branch 'devs/iscaro/ecore_evas_vnc_multiseat'

This series adds the Ecore_Evas multi-seat VNC support
using the software X11 backend.
This implementation tries to mimic the Wayland's multi-seat support.

This series also introduces two new kinds of EFL events, which are:
 * EFL_CANVAS_EVENT_DEVICE_ADDED - Which is emitted every
   time an Evas_Device is created.
 * EFL_CANVAS_EVENT_DEVICE_REMOVED - Which is emmited every
   time an Evas_Device is removed/deleted.

The new events are useful when one wants to monitor how many
and what kind of devices are connected to the system.

Patches by iscaro.
Differential Revision: https://phab.enlightenment.org/D4295

@feature