webos-keyboard: bump SRCREV and inherit webos_system_bus

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
Bump SRCREV for some components

Changes for webos-system-update:

4977884 Start application with correct environment settings

Changes for luna-next:

d4223ad plugins: compositor: extend CompositorWindow class with userData property
817b666 Inject StatusBarServicesConnector as context property rather than as singleton type
b9fb952 Implement WindowModel component
888eef6 plugins: compositor: remove direct rendering calls as API was removed upstream

Signed-off-by: Simon Busch <morphis@gravedo.de>