add tooltips to buttons

add tooltips for buttons on instances and tables.
![screen shot 2014-12-02 at 11 18 39 pm](https://cloud.githubusercontent.com/assets/972181/5276178/997ac6f0-7a79-11e4-8179-d42a5753d520.png)
![screen shot 2014-12-02 at 11 18 21 pm](https://cloud.githubusercontent.com/assets/972181/5276179/a2a2543c-7a79-11e4-9843-9a782395c6bb.png)
![screen shot 2014-12-02 at 11 18 01 pm](https://cloud.githubusercontent.com/assets/972181/5276180/a48e2618-7a79-11e4-974e-2c9a1a3fc238.png)