Enable/Unprefix Animations & Transitions, add basic tests

sky/engine/core/css/StylePropertySet.h

Index: sky/engine/core/css/StylePropertySet.h
diff --git a/sky/engine/core/css/StylePropertySet.h b/sky/engine/core/css/StylePropertySet.h
index 02c295af92aa7fe5f7d119c2b2331abfba16bb7e..afbbfbd04fd043bbd0fdff182fdc867de3027682 100644
--- a/sky/engine/core/css/StylePropertySet.h
+++ b/sky/engine/core/css/StylePropertySet.h
@@ -193,19 +193,15 @@ public:
     // These do not. FIXME: This is too messy, we can do better.
     bool setProperty(CSSPropertyID, CSSValueID identifier, bool important = false);
     bool setProperty(CSSPropertyID, CSSPropertyID identifier, bool important = false);
-    void appendPrefixingVariantProperty(const CSSProperty&);
-    void setPrefixingVariantProperty(const CSSProperty&);
+    void appendProperty(const CSSProperty&);
     void setProperty(const CSSProperty&, CSSProperty* slot = 0);
 
     bool removeProperty(CSSPropertyID, String* returnText = 0);
-    void removePrefixedOrUnprefixedProperty(CSSPropertyID);
     void removeBlockProperties();
     bool removePropertiesInSet(const CSSPropertyID* set, unsigned length);
     void removeEquivalentProperties(const StylePropertySet*);
     void removeEquivalentProperties(const CSSStyleDeclaration*);
 
-    void mergeAndOverrideOnConflict(const StylePropertySet*);
-
     void clear();
     void parseDeclaration(const String& styleDeclaration, StyleSheetContents* contextStyleSheet);