Merge remote-tracking branch 'origin/i20' into i24

Conflicts:
	sandbox/prototype/common/pom.xml
	sandbox/prototype/exec/java-exec/pom.xml
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/opt/BasicOptimizer.java
	sandbox/prototype/pom.xml
Merge branch 'i20' of https://github.com/XingCloud/incubator-drill into i20

Conflicts:
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/physical/config/HbaseUserScanPOP.java
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/store/HBaseUserRecordReader.java
	sandbox/prototype/exec/java-exec/src/test/java/org/apache/drill/exec/store/TestHBaseAbstractRecordReader.java
	sandbox/prototype/outer-app/src/test/java/org/apache/drill/outer/manual/TestManualLPCommon.java
	sandbox/prototype/outer-app/src/test/java/org/apache/drill/outer/manual/TestManualLPGroupByMin5.java
	sandbox/prototype/outer-app/src/test/java/org/apache/drill/outer/manual/TestManualLPGroupByUser.java
Merge branch 'i20' of https://github.com/XingCloud/incubator-drill into i20
Merge branch 'i20' of https://github.com/XingCloud/incubator-drill into i20

Conflicts:
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/physical/config/HbaseUserScanPOP.java
	sandbox/prototype/exec/java-exec/src/main/java/org/apache/drill/exec/store/HBaseUserRecordReader.java
	sandbox/prototype/exec/java-exec/src/test/java/org/apache/drill/exec/store/TestHBaseAbstractRecordReader.java
	sandbox/prototype/outer-app/src/test/java/org/apache/drill/outer/manual/TestManualLPCommon.java
	sandbox/prototype/outer-app/src/test/java/org/apache/drill/outer/manual/TestManualLPGroupByMin5.java
	sandbox/prototype/outer-app/src/test/java/org/apache/drill/outer/manual/TestManualLPGroupByUser.java
Merge branch 'i20' of https://github.com/XingCloud/incubator-drill into i20
.
UserSegment is done.
Merge branch 'i20' of https://github.com/XingCloud/incubator-drill into i20