Front Page averages, revision summaries, histogram of fails/skips

https://github.com/gwicke/testreduce/issues/17 : averages of skip/fail/error calculated in getStatistics, saved to revision summary table in updateCommit. Also changed the score function to be 10000*failscount.
 
https://github.com/gwicke/testreduce/issues/38 : finished failsDistr and skipsDistr. Finished frontend of failedFetches. Still need to figure out where to save the failed fetches info.