Improve saved search email layout [MJ-750]

Displays company logos, company names, job locations, and total job counts in saved search emails. Company information is not available in the rss feed, so we transparently use the json feed if a saved search appears to have been made from a microsite (has 'feed/rss' in the feed url).

Attached is a more recent screenshot of the title of a saved search as viewed on a mobile device. Desktop viewing and the remainder of mobile viewing are unchanged from the most recent shots posted on Jira. The purple text is only purple because of how Gmail handles nearly identical emails.

![screenshot_2014-02-27-09-22-09](https://f.cloud.github.com/assets/3379265/2286191/766385ec-9fde-11e3-80b9-6e0493242dc9.png)

All tests pass.