FLUME-1382: Flume adopt message from existing local Scribe

Implementation of ScribeSource allowing flume to receive messages from scribe, or any other agent using the thrift/scribe protocol
(Danny Ye via Juhani Connolly)
FLUME-1490. Option to limit number of events sent in Stress source.

(Patrick Wendell via Will McQueen)
FLUME-1437: Checkpoint can miss pending takes

(Hari Shreedharan via Brock Noland)
FLUME-1498. File channel log updates and queue updates should be atomic.

(Brock Noland via Hari Shreedharan)
FLUME-1504: Test file channel times out randomly

(Hari Shreedharan via Brock Noland)
FLUME-1505. TestFileChannel needs to be able to force a checkpoint.

(Brock Noland via Hari Shreedharan)
FLUME-1489. Flume Scribe Source should be included in source and dist tarballs.

(Juhani Connolly via Hari Shreedharan)
FLUME-1492. Create integration test for file channel.

(Will McQueen via Mike Percy)
FLUME-1508. TestFileChannel times out maven periodically.

(Brock Noland via Hari Shreedharan)
FLUME-1500 Upgrade flume to use latest version of Avro - v1.7

(Hari Shreedharan via Mubarak Seyed)
FLUME-1512: File Channel should not stop during a checkpoint

(Hari Shreedharan via Brock Noland)
FLUME-1428: File Channel should not consider a file as inactive until all takes are committed

(Hari Shreedharan via Brock Noland)
FLUME-1513: File Channel log close() method should not be synchronized

(Hari Shreedharan via Brock Noland)
FLUME-1524. Fix flaky MonitoredCounterGroup test.

(Mike Percy via Hari Shreedharan)
FLUME-1523. Allow -X java opts to be passed to the agent on the command line.

(Mike Percy via Hari Shreedharan)
FLUME-1525. Increase test timeouts.

(Brock Noland via Hari Shreedharan)
FLUME-1496: TestFileChannel is bloated

(Hari Shreedharan via Brock Noland)
FLUME-1527. Seed TransactionID/WriteOrderID in the case no logs need to be replayed.

(Brock Noland via Hari Shreedharan)
FLUME-1528: File Channel replay when no checkpoint is present can be faster

(Hari Shreedharan via Brock Noland)
FLUME-1531. Flume User Guide should provide more details on configuring the timestamp interceptor.

(Kathleen Ting via Hari Shreedharan)