FLUME-2126. Problem in elasticsearch sink when the event body is a complex field

(Ashish Paliwal via Hari)
FLUME-1710. JSONEvent.getBody should not return null

(Ashish Paliwal via Hari)
FLUME-2482. File Channel tests must disable scheduled checkpoint to avoid a race condition with forced checkpoint.

(Johny Rufus via Hari)
Merge remote-tracking branch 'remotes/origin/trunk' into trunk