Tomato: initial commit of mask editing tools into SVN

- Added new dtaablock called Mask which might be re-used in any area.
  Currently editing of masks happens in clip editor and they might be used in
  compositor nodes only.
- Added new mode to clip clip editor to interact with masks.
  Implemented basic tools to create shapes, splines and points. Also implemented
  idea of UW points for feather which means feather points are have got U
  coordinate along spline (which is measured from 0 to 1) and W is it's weight
  meaning distance from main spline.
- Spline points might be parented to movie tracks.
  Interface for this isn't best yet.
- Rasterisaztion of masks happens in compositor node (Input -> Mask)
  Input image of this ode is used as reference for mask resolution.
  Currently all splines of all shapes are rasterizing independently which
  means shapes with holes are not supported.
  Also feather rasterization is not implemented.

  Rasterized was implemented by Pete Larbell, thanks!

Do not consider this is something finished, there's still lots of things to
be done (especially from interface and usability points of view).

source/blender/editors/interface/interface_templates.c

@@ -576,8 +576,10 @@ void uiTemplateAnyID(uiLayout *layout, PointerRNA *ptr, const char *propname, co
 	row = uiLayoutRow(layout, 1);
 	
 	/* Label - either use the provided text, or will become "ID-Block:" */
-	if (text)
-		uiItemL(row, text, ICON_NONE);
+	if (text) {
+		if (text[0])
+			uiItemL(row, text, ICON_NONE);
+	}
 	else
 		uiItemL(row, "ID-Block:", ICON_NONE);