support Tree & add dispatch and broadcast methods

support Tree，many component add name $option；add dispatch and broadcast
methods, mixins it

src/mixins/emitter.js

@@ -0,0 +1,33 @@
+function broadcast(componentName, eventName, params) {
+    this.$children.forEach(child => {
+        const name = child.$options.name;
+
+        if (name === componentName) {
+            child.$emit.apply(child, [eventName].concat(params));
+        } else {
+            broadcast.apply(child, [componentName, eventName].concat([params]));
+        }
+    });
+}
+export default {
+    methods: {
+        dispatch(componentName, eventName, params) {
+            let parent = this.$parent || this.$root;
+            let name = parent.$options.name;
+
+            while (parent && (!name || name !== componentName)) {
+                parent = parent.$parent;
+
+                if (parent) {
+                    name = parent.$options.name;
+                }
+            }
+            if (parent) {
+                parent.$emit.apply(parent, [eventName].concat(params));
+            }
+        },
+        broadcast(componentName, eventName, params) {
+            broadcast.call(this, componentName, eventName, params);
+        }
+    }
+};