Default to order search results by '-modified'
Default to order search results by '-modified'

This will make searches better.  Most of the time you want recent results, not
oldest ones.

Author: Isaac Levy <ilevy@chromium.org>

Review: https://codereview.appspot.com/6814091/

riannucci/rietveldv2,riannucci/rietveldv2