Adding a search box to the groups screen

I took the following steps:
* on the overview/show screen for my bulk message conversation
* I click on the 'edit' button next to the "contacts' header
* I am directed to the 'contacts-edit' screen

We need to have a search box on the 'contacts-edit' screen that a user can use to search across contact (smart and regular) groups.

This is a requirement for Rachel from Sisi Ni Amani who has hundreds of groups in her account.

This ticket is dependent on #637 

![screen shot 2013-08-19 at 1 36 20 pm](https://f.cloud.github.com/assets/1521387/985627/85a8dac8-08c3-11e3-883f-957b0da03055.png)

![screen shot 2013-08-19 at 1 27 35 pm](https://f.cloud.github.com/assets/1521387/985631/91045456-08c3-11e3-9d58-f222faa5bcc1.png)