weston-ivi-shell: Update ivi-layout-export.h

Signed-off-by: James Thomas <james.thomas@codethink.co.uk>
weston-ivi-shell and ilmControl: Implement 'set keyboard focus'

This commit implements ilm_SetKeyboardFocusOn by using the "ivi
controller surface" interface, implementing the specific case
of keyboard focus.

It expands ivi-layout.h and ivi-layout-export.h so that keyboard
focus can be stored on a per-surface basis.

Signed-off-by: James Thomas <james.thomas@codethink.co.uk>
weston-ivi-shell, ilmControl and ilmCommon: Implement GetKeyboardFocus

This commit implements ilm_GetKeyboardFocusSurfaceId using the "input
focus" event from the "ivi controller surface" interface.

ilm_types.h has been expanded to store keyboard focus on a per-surface
basis.

Signed-off-by: James Thomas <james.thomas@codethink.co.uk>
test: Fix keyboard focus test

This fixes the test IlmCommandTest.ilm_keyboard_focus.

Signed-off-by: James Thomas <james.thomas@codethink.co.uk>
Add EGLWLInputEventExample example application
Add command-line option for surface to EGLWLInputEventExample
ivi-layermanagement-examples: EGLWLInputEventExapmle to be built with
non-default directly.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>