Stop inheriting SVGExternalResourcesRequired, SVGFitToViewBox and SVGZoomAndPan
https://bugs.webkit.org/show_bug.cgi?id=118029

Reviewed by Kentaro Hara.

Stop inheriting SVGExternalResourcesRequired, SVGFitToViewBox and SVGZoomAndPan
in the IDL and use implements statements instead.

This is one step towards getting rid of multiple inheritance in the SVG code
and matching the latest specification:
http://www.w3.org/TR/SVG2/types.html#BasicDOMInterfaces

There is no webexposed behavior change.

No new tests, no behavior change.

* svg/SVGAnimationElement.idl:
* svg/SVGCircleElement.idl:
* svg/SVGClipPathElement.idl:
* svg/SVGCursorElement.idl:
* svg/SVGDefsElement.idl:
* svg/SVGEllipseElement.idl:
* svg/SVGFEImageElement.idl:
* svg/SVGFilterElement.idl:
* svg/SVGForeignObjectElement.idl:
* svg/SVGGElement.idl:
* svg/SVGGradientElement.idl:
* svg/SVGImageElement.idl:
* svg/SVGLineElement.idl:
* svg/SVGMPathElement.idl:
* svg/SVGMarkerElement.idl:
* svg/SVGMaskElement.idl:
* svg/SVGPathElement.idl:
* svg/SVGPatternElement.idl:
* svg/SVGPolygonElement.idl:
* svg/SVGPolylineElement.idl:
* svg/SVGRectElement.idl:
* svg/SVGSVGElement.idl:
* svg/SVGScriptElement.idl:
* svg/SVGSwitchElement.idl:
* svg/SVGSymbolElement.idl:
* svg/SVGTextContentElement.idl:
* svg/SVGUseElement.idl:
* svg/SVGViewSpec.idl:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@151988 268f45cc-cd09-0410-ab3c-d52691b4dbfc