[SPARK-4295][External]Fix exception in SparkSinkSuite

Handle exception in SparkSinkSuite, please refer to [SPARK-4295]

Author: maji2014 <maji3@asiainfo.com>

Closes #3177 from maji2014/spark-4295 and squashes the following commits:

312620a [maji2014] change a new statement for spark-4295
24c3d21 [maji2014] add log4j.properties for SparkSinkSuite and spark-4295
c807bf6 [maji2014] Fix exception in SparkSinkSuite

(cherry picked from commit f8811a5695af2dfe156f07431288db7b8cd97159)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
[SPARK-2492][Streaming] kafkaReceiver minor changes to align with Kafka 0.8

Update the KafkaReceiver's behavior when auto.offset.reset is set.

In Kafka 0.8, `auto.offset.reset` is a hint for out-range offset to seek to the beginning or end of the partition. While in the previous code `auto.offset.reset` is a enforcement to seek to the beginning or end immediately, this is different from Kafka 0.8 defined behavior.

Also deleting extesting ZK metadata in Receiver when multiple consumers are launched will introduce issue as mentioned in [SPARK-2383](https://issues.apache.org/jira/browse/SPARK-2383).

So Here we change to offer user to API to explicitly reset offset before create Kafka stream, while in the meantime keep the same behavior as Kafka 0.8 for parameter `auto.offset.reset`.

@tdas, would you please review this PR? Thanks a lot.

Author: jerryshao <saisai.shao@intel.com>

Closes #1420 from jerryshao/kafka-fix and squashes the following commits:

d6ae94d [jerryshao] Address the comment to remove the resetOffset() function
de3a4c8 [jerryshao] Fix compile error
4a1c3f9 [jerryshao] Doc changes
b2c1430 [jerryshao] Move offset reset to a helper function to let user explicitly delete ZK metadata by calling this API
fac8fd6 [jerryshao] Changes to align with Kafka 0.8

(cherry picked from commit c8850a3d6d948f9dd9ee026ee350428968d3c21b)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
[Streaming][Minor]Replace some 'if-else' in Clock

Replace some 'if-else' statement by math.min and math.max in Clock.scala

Author: huangzhaowei <carlmartinmax@gmail.com>

Closes #3088 from SaintBacchus/StreamingClock and squashes the following commits:

7b7f8e7 [huangzhaowei] [Streaming][Minor]Replace some 'if-else' in Clock

(cherry picked from commit 6e03de304e0294017d832763fd71e642736f8c33)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>