Log Message:
py-xcbgen: update to 1.13.

This release of xcb-proto brings support for buffer modifiers and
multi-planar buffers through DRI3 v1.2 and Present v1.2, support for
leasing KMS devices to clients via RandR 1.6, and also allows clients
to send each other XInput2 events via support for the GenericEvent
extension's SendExtension event.