LOGSTASH-1003 LOGSTASH-1038 fixing both issues in one commit because the rabbitmq input is functionally broken until both are fixed
Added more information for building from git

Added make vendor-elasticsearch for getting jars out of elasticsearch for running from git.
Merge pull request #463 from timconradinc/patch-2

Added more information for building from git
Merge pull request #459 from jkoppe/jkoppe-bunny-rabbitmq-fixes

Fixing both LOGSTASH-1003 and LOGSTASH-1038
Merge git://github.com/logstash/logstash