First implementation of search in files

The placeholder text to show when the view is empty still needs to be implemented.

fixed #859

review: @devoncarew

![screen shot 2014-07-19 at 10 43 21 am](https://cloud.githubusercontent.com/assets/332168/3635348/380d40e6-0f6c-11e4-875f-cbbaef91e7cf.png)

Can you add a TODO: - we'll want to highlight the matching term in the line, and probably add ellipses to the left side of the line as well, if the matching term is further into the line. Something like:

...foo bar __matching term__ and then more...