Added margin to align select date icons on timesheet view

Before: 
![image](https://f.cloud.github.com/assets/1164911/1062652/9ebbe158-1260-11e3-9a44-fb6261ba9be6.png)

After: 
![image](https://f.cloud.github.com/assets/1164911/1062653/a8f130ba-1260-11e3-9dcc-76ffcfd20680.png)

Tested on latest Firefox and Chrome (Win 7).