refactor(EventEmitter): rename .next() to .emit()

BREAKING CHANGE:

EventEmitter#next(value) is deprecated, use EventEmitter#emit(value)
instead.

Closes #4287

Closes #5302

modules/angular2/test/common/forms/integration_spec.ts

@@ -990,7 +990,7 @@ class MyInput implements ControlValueAccessor {
   registerOnTouched(fn) {}
 
   dispatchChangeEvent() {
-    ObservableWrapper.callNext(this.onChange, this.value.substring(1, this.value.length - 1));
+    ObservableWrapper.callEmit(this.onChange, this.value.substring(1, this.value.length - 1));
   }
 }
 

modules/angular2/test/common/forms/model_spec.ts

@@ -37,7 +37,7 @@ export function main() {
 
   function asyncValidatorReturningObservable(c) {
     var e = new EventEmitter();
-    PromiseWrapper.scheduleMicrotask(() => ObservableWrapper.callNext(e, {"async": true}));
+    PromiseWrapper.scheduleMicrotask(() => ObservableWrapper.callEmit(e, {"async": true}));
     return e;
   }
 

modules/angular2/test/common/forms/validators_spec.ts

@@ -101,9 +101,9 @@ export function main() {
           var res = c.value != expected ? response : null;
 
           PromiseWrapper.scheduleMicrotask(() => {
-            ObservableWrapper.callNext(emitter, res);
+            ObservableWrapper.callEmit(emitter, res);
             // this is required because of a bug in ObservableWrapper
-            // where callComplete can fire before callNext
+            // where callComplete can fire before callEmit
             // remove this one the bug is fixed
             TimerWrapper.setTimeout(() => { ObservableWrapper.callComplete(emitter); }, 0);
           });