feat: support binding to style.stylename.suffix

Closes #553

modules/angular2/src/facade/dom.dart

@@ -120,6 +120,16 @@ class DOM {
   static bool hasClass(Element element, String classname) =>
       element.classes.contains(classname);
 
+  static setStyle(Element element, String stylename, String stylevalue) {
+      element.style.setProperty(stylename, stylevalue);
+  }
+  static removeStyle(Element element, String stylename) {
+      element.style.removeProperty(stylename);
+  }
+  static getStyle(Element element, String stylename) {
+      return element.style.getPropertyValue(stylename);
+  }
+
   static String tagName(Element element) => element.tagName;
 
   static Map<String, String> attributeMap(Element element) =>

modules/angular2/src/facade/dom.es6

@@ -139,6 +139,15 @@ export class DOM {
   static hasClass(element:Element, classname:string) {
     return element.classList.contains(classname);
   }
+  static setStyle(element:Element, stylename:string, stylevalue:string) {
+    element.style[stylename] = stylevalue;
+  }
+  static removeStyle(element:Element, stylename:string) {
+    element.style[stylename] = null;
+  }
+  static getStyle(element:Element, stylename:string) {
+    return element.style[stylename];
+  }
   static tagName(element:Element):string {
     return element.tagName;
   }