* Mono.Cairo/Cairo.cs (cairo_set_target_drawable): Not available anymore, removed.

* Mono.Cairo/Cairo.cs (cairo_set_target_drawable): Not available anymore, removed.
(cairo_reference, cairo_arc, cairo_arc_negative): New API, added.
(cairo_current_matrix): Signature changed, updated.
(cairo_surface_reference): New API.
(cairo_surface_get_matrix): Use 'out' instead of 'ref' param.

* Mono.Cairo/Surface.cs:
* Mono.Cairo/Object.cs: Added binding for new APIs listed in Cairo.cs.
(Destroy): It's supposed to return void, not IntPtr.

* cairo-api.cs: Marked as in internal class, instead of
public. Update to new Cairo API (see Mono.Cairo/Cairo.cs).

* gdk-helpers.cs (Gdk.Pixbuf.Finalize): Removed.

svn path=/trunk/mcs/; revision=18901