Revert "FLUME-2338. Support coalescing increments in HBaseSink."

This reverts commit 674f4fcce2597e7e934ccc69eb04b426f5a9b8bb.
FLUME-2338. Support coalescing increments in HBaseSink.

(Mike Percy via Hari Shreedharan)
Merge remote-tracking branch 'remotes/origin/trunk' into trunk