LOGSTASH-1118 - Option to add event fields from SQS message ID & MD5
- attempt to rewrite the twitter input to use TweetStream. It seems
  mostly unsuccessful so far.

  This is necessarily because twitter has disabled both the v1 api and
  no longer permits basic http authentication. This largely complicates
  the first-time setup for all users of this plugin :(
- check config_name, too
- fix bug where multiple outputs would compile to invalid ruby (oops)
- disable twitter input. sigh.
Merge pull request #509 from semiosis/LOGSTASH-1118

LOGSTASH-1118 - Option to add event fields from SQS message ID & MD5
Only load plugins by their config_name
Refactor to use Stud::Buffer. This now permits idle flushing, so it will no longer wait until a full buffer to flush. weeeeeee!
- do tags/type settings (TODO: refactor this into the codec somewhow?)
- make the default stdin input (for the -e flag) set type => stdin
  No strong reason for this, just might be useful for testing.
Note that the twitter input is now broken
- refactor to use Stud::Buffer and bulk index requests.
- fix flushing and index_type settings
- make setup_log4j a class method
- obey logging style guide
facepalm-oriented bug fix in test runner

This commit fixes an old bug where 'make flatjar-test' (run rspecs from
the jar) would run only the first spec file in the args list. Oops.
- permit comments to have no content following them.
YAML no longer supported
Fix broken tests
- don't need to specify the 'database' anymore, woot.