fix(di/exceptions): initialize Error superclass with message

For subclasses of Error, initializing classes without providing a 
message to super() would cause any messages to be suppressed from
logged errors. This fix provides an initial message to super().

Fixes angular#2570

modules/angular2/src/di/exceptions.ts

@@ -37,7 +37,7 @@ export class AbstractBindingError extends BaseException {
   constructResolvingMessage: Function;
   // TODO(tbosch): Can't do key:Key as this results in a circular dependency!
   constructor(key, constructResolvingMessage: Function) {
-    super();
+    super(constructResolvingMessage([key]));
     this.keys = [key];
     this.constructResolvingMessage = constructResolvingMessage;
     this.message = this.constructResolvingMessage(this.keys);

modules/angular2/test/di/exceptions_spec.dart

@@ -0,0 +1,3 @@
+library angular2.test.di.exceptions_spec;
+// Not implemented
+main() {}

modules/angular2/test/di/exceptions_spec.ts

@@ -0,0 +1,23 @@
+import {
+  AsyncTestCompleter,
+  beforeEach,
+  ddescribe,
+  describe,
+  expect,
+  iit,
+  inject,
+  it,
+  xit,
+} from 'angular2/test_lib';
+import {AbstractBindingError} from 'angular2/di';
+
+export function main() {
+        describe('exceptions', () => {
+    it('should have the proper message when thrown', () => {
+      try {
+        throw new AbstractBindingError('foo', () => { return 'message'; });
+      } catch (e) {
+        expect(e.stack.split('\n')[0]).toBe('Error: message');
+      }
+    });
+}