Adding "vector-effect" as recognized property.

W3 Spec: https://www.w3.org/TR/SVGTiny12/painting.html#NonScalingStroke
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=116700921

Author: iflan

src/com/google/common/css/compiler/ast/Property.java

@@ -539,6 +539,7 @@ public final class Property {
         builder("transition"),
         builder("unicode-bidi"),
         builder("unicode-range"),
+        builder("vector-effect").isSvgOnly(),
         builder("vertical-align"),
         builder("visibility"),
         builder("voice-balance"),