Reviewed by Dirk Schulze.

        Convert SVGAngle to the new SVGPropertyTearOff concept, reimplement it properly
        https://bugs.webkit.org/show_bug.cgi?id=48179

        Rewrite SVGAngle to use the new SVGPropertyTearOff concept, and consume much less memory.
        Down from two floats, one string and an ushort to one float and one ushort. Synchronize value/valueInSpecifiedUnits/valueAsString on demand.

        Adding an extensive SVGAngle test, that required to implement 'StrictTypeChecking' for attribute setters (was only implemented in V8/JSC for function cals so far).

        Test: svg/dom/SVGAngle.html

        * GNUmakefile.am: Add SVGAnimatedAngle.h to build.
        * WebCore.gypi: Ditto.
        * WebCore.pro: Ditto.
        * WebCore.vcproj/WebCore.vcproj: Ditto.
        * WebCore.xcodeproj/project.pbxproj: Ditto.
        * bindings/scripts/CodeGenerator.pm: Split IsPrimitiveType in IsPrimitiveType and IsNumericType.
     ...