AddDateTimeAndImageBackGround

**update**
1. add date & time pickers on `Dialog`;
2. experiment image background;
3. make some ui polish including status icons and restaurant title font in `Detail`;
4. add cancel button in `Dialog`.

**issue**
1. date & time don't display in full after reducing size;
2. tried using `ImageButton` for `Cancel` and `Invite` on `Dialog` but failed to work; throws "icon not valid drawable" error;
3. tried to resize `map` on detail page but failed to work.

**to-do**
1. image background updates by restaurants;
2. push object with date & time;
3. polish `FoodieUser` list view on `Dialog`.

**screenshot**
![foodie](https://f.cloud.github.com/assets/1649569/2257478/466c13ec-9e1a-11e3-994c-dd585a0d9246.jpg)