feat(SebmGoogleMap): support draggableCursor opt

Closes #234

src/directives/google-map.ts

@@ -34,7 +34,7 @@ import {MouseEvent} from '../events';
   providers: [GoogleMapsAPIWrapper, MarkerManager],
   inputs: [
     'longitude', 'latitude', 'zoom', 'disableDoubleClickZoom', 'disableDefaultUI', 'scrollwheel',
-    'backgroundColor'
+    'backgroundColor', 'draggableCursor'
   ],
   outputs: ['mapClick', 'mapRightClick', 'mapDblClick', 'centerChange'],
   host: {'[class.sebm-google-map-container]': 'true'},
@@ -76,10 +76,19 @@ export class SebmGoogleMap implements OnChanges,
    */
   backgroundColor: string;
 
+  /**
+   * The name or url of the cursor to display when mousing over a draggable map. This property uses
+   * the css  * cursor attribute to change the icon. As with the css property, you must specify at
+   * least one fallback  * cursor that is not a URL. For example:
+   * draggableCursor="'url(http://www.example.com/icon.png), auto;'"
+   */
+  draggableCursor: string;
+
   /**
    * Map option attributes that can change over time
    */
-  private static _mapOptionsAttributes: string[] = ['disableDoubleClickZoom', 'scrollwheel'];
+  private static _mapOptionsAttributes: string[] =
+      ['disableDoubleClickZoom', 'scrollwheel', 'draggableCursor'];
 
   /**
    * This event emitter gets emitted when the user clicks on the map (but not when they click on a
@@ -117,7 +126,8 @@ export class SebmGoogleMap implements OnChanges,
       center: {lat: this._latitude, lng: this._longitude},
       zoom: this._zoom,
       disableDefaultUI: this.disableDefaultUI,
-      backgroundColor: this.backgroundColor
+      backgroundColor: this.backgroundColor,
+      draggableCursor: this.draggableCursor
     });
     this._handleMapCenterChange();
     this._handleMapZoomChange();

src/services/google-maps-types.ts

@@ -59,4 +59,5 @@ export interface MapOptions {
   disableDoubleClickZoom?: boolean;
   disableDefaultUI?: boolean;
   backgroundColor?: string;
+  draggableCursor?: string;
 }