fix build (missing marshaller)
input-device: add enter/leave events generation for touch events

This patch brings 'enter-event' and 'leave-event' generation for touch
based devices. This leads to adding a new API to retrieve coordinates
of a touch point.

https://bugzilla.gnome.org/show_bug.cgi?id=679797
input-device: fix destroy signal connection on wrong actor
Updated POTFILES.in
Fix compiler warning

Mark a variable as unused.
input-device: Fix introspection annotation

The event sequence can be %NULL.
x11: Add debug notes for pointer-emulated
event: Copy the is-pointer-emulated flag

https://bugzilla.gnome.org/show_bug.cgi?id=680174
event: Expose is-pointer-emulated flag

Clutter on X11 already stores this flag to distinguish between events
that have been synthesized by the X server and real events.

https://bugzilla.gnome.org/show_bug.cgi?id=680174
docs: Add missing section for ClutterRotateAction
Split off LayoutManager deprecated functions to a separate file

This should make it easier to clean up later when we branch off for
1.99.
actor: Consolidate rotation angle internal setter

Use the GParamSpec, instead of the rotation axis enumeration, to
simplify the caller code, similarly to how we handle scaling and
translation factors.
interactive/animation: Use pivot point

Instead of the anchor point and the rotation center.
timeline: Add support for step() progress

The CSS3 Transitions specification from the W3C defines the possibility
of using a parametrized step() timing function, with the following
prototype:

        steps(n_steps, [ start | end ])

where @n_steps represents the number of steps used to divide an interval
between 0 and 1; the 'start' and 'end' tokens describe whether the value
change should happen at the start of the transition, or at the end.

For instance, the "steps(3, start)" timing function has the following
profile:

  1 |           x
    |           |
    |       x---|
    |       '   |
    |   x---'   |
    |   '       |
  0 |---'       |

Whereas the "steps(3, end)" timing function has the following profile:

  1 |       x---|
    |       '   |
    |   x---'   |
    |   '       |
    x---'       |
    |           |
  0 |           |

Since ClutterTimeline uses an enumeration for controlling the progress
mode, we need additional API to define the parameters of the steps()
progress; for this reason, we need a CLUTTER_STEPS enumeration value,
and a method for setting the number of steps and the value transition
policy.

The CSS3 Transitions spec helpfully also defines a step-start and a
step-end shorthands, which expand to step(1, start) and step(1, end)
respectively; we can provide a CLUTTER_STEP_START and CLUTTER_STEP_END
enumeration values for those.
timeline: Add cubic-bezier() progress functions

Another progress function from the CSS3 Transitions specification, using
a parametrices cubic bezier curve between (0, 0) and (1, 1) with two
control points.

(sadly, no ASCII art can approximate a cubic bezier, so no graph)

The cubic-bezier() progress function comes with a bunch of preset easing
modes: ease, ease-in, ease-out, and ease-in-out, that we can map to
enumeration values.
examples/easing-modes: Use newly added modes

Step and cubic bezier.
Updated Greek translation
Updated Serbian translation
actor: Add ::transition-stopped

The ::transition-stopped signal can be used to get notification of the
end of a transition.
actor: Simplify the implicit transition handling

We can remove the update_transition() private method, and move its
functionality inside the create_transition() private method, thereby
removing lots of duplicated code, as well as redundant checks on the
existence of a transition. This will allow handling transition updates
atomically in the future.