Checking in all external files needed for mapreduce

This is just checking in a bunch of resources. It doesn't affect the
build.
Config and environment changes for mapreduce

Main change: Update appengine SDK to 1.8.0. Required for mapreduce.
Other minor changes:
* Added relevant JARs to the build path
* Added new queues for mapreduce
* Added new servlet mappings in web.xml for mapreduce
First mapreduce job: Daily impressions

Currently still piggy back on existing CRON jobs.
Creation of a new storage entity: DailyStats.