Fix unable to parse error(As reported by SJoseph)

Ignore EOFError raised by stderrout.read_nonblock, since with
sufficiently big stdout, small stderrout and small buffer_size, err
will reach EOF before the stdout is completely read. This would
cause the graders output to be truncated.
Remove unnecessary comments.
Reload graders' config after sleep on edx client

Every time edx_client wakes from sleep it reloads the autograders'
config.
Merge pull request #11 from gspilio/unable_to_parse_fix

Unable to parse fix
Merge pull request #12 from gspilio/reload_config

Reload config