Fix some bugs for the project

1.Fix the bug of cancel button in the search bar
![image](https://cloud.githubusercontent.com/assets/3123644/2728678/5fb69712-c5f9-11e3-9cc0-3837d6896622.png)
2.Fix the bug of pushing view in the search result
![image](https://cloud.githubusercontent.com/assets/3123644/2728695/c09b0798-c5f9-11e3-8133-f0315c30a1e7.png)
3.Fix the bug that only display part of bus lines in the all bus lines' view.
![image](https://cloud.githubusercontent.com/assets/3123644/2728708/155eec04-c5fa-11e3-8a34-237feeabe20e.png)