Add possibility to booked membership

![zrzut ekranu z 2014-10-31 11 15 18](https://cloud.githubusercontent.com/assets/6718923/4860394/3d405a62-60f7-11e4-8358-9b04ca48718a.png)
![zrzut ekranu z 2014-10-31 12 56 01](https://cloud.githubusercontent.com/assets/6718923/4860393/3d3db97e-60f7-11e4-969d-6ab1f37cb6fb.png)
![zrzut ekranu z 2014-10-31 12 56 07](https://cloud.githubusercontent.com/assets/6718923/4860395/3d474700-60f7-11e4-84f4-6acd0057d5ff.png)
![zrzut ekranu z 2014-10-31 13 00 17](https://cloud.githubusercontent.com/assets/6718923/4860396/3d476320-60f7-11e4-81af-269461375215.png)