Changes to handle inconsistencies in spam judgments

Made it so Video-only tasks are not compared against Gold Standards and
average comparisons.
Fixed issue where a couple of Fragments had no transcription, and
needed to avoid marking as spam any HITs that had no judgements for
these tasks.
Merge branch 'master' into aelshen_branch
Updated the script to produce CSVs with reject notes, to automate the process
Merge branch 'aelshen_branch'