feat(Directive): Have a single Directive.host which mimics HTML

fixes #2268

BREAKING CHANGE:

Before

    @Directive({
      hostListeners: {'event': 'statement'},
      hostProperties: {'expression': 'hostProp'},
      hostAttributes: {'attr': 'value'},
      hostActions: {'action': 'statement'}
    })

After

    @Directive({
      host: {
        '(event)': 'statement',
        '[hostProp]': 'expression'  // k & v swapped
        'attr': 'value',
        '@action': 'statement'
      }
    })

modules/angular2/test/render/api_spec.ts

@@ -0,0 +1,26 @@
+import {DirectiveMetadata} from 'angular2/src/render/api';
+
+import {MapWrapper} from 'angular2/src/facade/collection';
+import {ddescribe, describe, expect, it} from 'angular2/test_lib';
+
+export function main() {
+  describe('Metadata', () => {
+    describe('host', () => {
+      it('should parse host configuration', () => {
+        var md = DirectiveMetadata.create({
+          host: MapWrapper.createFromPairs([
+            ['(event)', 'eventVal'],
+            ['[prop]', 'propVal'],
+            ['@action', 'actionVal'],
+            ['attr', 'attrVal']
+          ])
+        });
+
+        expect(md.hostListeners).toEqual(MapWrapper.createFromPairs([['event', 'eventVal']]));
+        expect(md.hostProperties).toEqual(MapWrapper.createFromPairs([['prop', 'propVal']]));
+        expect(md.hostActions).toEqual(MapWrapper.createFromPairs([['action', 'actionVal']]));
+        expect(md.hostAttributes).toEqual(MapWrapper.createFromPairs([['attr', 'attrVal']]));
+      });
+    });
+  });
+}