Search filters

Search filters are here!

![screen shot 2014-04-06 at 3 09 52 pm](https://cloud.githubusercontent.com/assets/9306/2626288/84c98972-bdc7-11e3-959c-a3a635b06051.png)
![screen shot 2014-04-06 at 3 10 08 pm](https://cloud.githubusercontent.com/assets/9306/2626289/84d49d80-bdc7-11e3-8e79-64edca4d8849.png)

Sparked by a recent review on the webstore, search filters adds a missing ux element. Seeing a search bar on week and day views leading you to expect you will be searching the week or day. This was not the current behavior. 

A nice side effect of this is that searching is way faster because the week and day search filters are enabled by default and use the built in start time and end time search filtering in the history api.