remove utc format from es index, use elasticsearch-ruby lib instead of pure http, add flush_size as in logstash-elasticsearch plugin
Add simple test code; change flush_size to integer type
Add utc_index option and corresponding testcase, modify runtime dependencies
Merge remote-tracking branch 'xia0pin9/new-fluent-elasticsearch' into apply-elasticsearch-clustered-feature

* fixed some errors about typo

Conflicts:
	lib/fluent/plugin/out_elasticsearch.rb
Fix numerous things from PR #26

- bug fixes
-- meta/record are not sent to ES when bulk_message.size grows and equals to @flush_size.
-- some typos
-- ES 1.x may request ping (request http://<ES>:9200/ with HEAD method), so we should stub it

- improvements
-- merge meta / record (2 lines) into one, then we could reduce network traffic and save round trip time

- library dependencies
-- use patron, recent typheous (0.6.7) is not compatible with recent faraday (0.9.0)
--- you need to install libcurl
--- do not ever install typheous, faraday will autoload typheous and maybe produce some problem!

- etc
-- arrange whitespaces for proper formatting
Fix bug in adding runtime dependency

* it uses patron, not typhoeus
Fix bugs to really working with ES

* client.bulk accepts array of hash, not json
* split content to meta and record (rollback thing)
** client.bulk splitted it to meta and record and send in specific elasticsearch-ruby version
** we cannot control unit tests, so rollback things
Respect code style to prevent unneeded diff
source formatting
Force faraday to use Patron

* also removed unneeded diff
New features : multiple hosts with load balanced

* thanks to elasticsearch-ruby, we can easily handle with multiple node with load balanced
** default is round robin, which would be fine with most situation, so I don't extract to configuration
** requests are per bulk, not per one data : so does load balancing
* include unit test: performing balanced request
describe "prerequisite" to README.md