Remove unused imports and local vars
PHOENIX-1338 Logic to group together parallel scans is incorrect

Conflicts:
	phoenix-core/src/it/java/org/apache/phoenix/end2end/BaseViewIT.java
	phoenix-core/src/main/java/org/apache/phoenix/iterate/ParallelIterators.java
PHOENIX-1313 Investigate why LocalIndexIT.testLocalIndexScanAfterRegionSplit() is failing(Rajeshbabu)

Conflicts:
	phoenix-core/src/main/java/org/apache/phoenix/iterate/ParallelIterators.java
PHOENIX-619 Support DELETE over table with immutable index when possible

Conflicts:
	phoenix-core/src/it/java/org/apache/phoenix/end2end/index/ViewIndexIT.java
	phoenix-core/src/main/java/org/apache/phoenix/compile/DeleteCompiler.java
	phoenix-core/src/main/java/org/apache/phoenix/optimize/QueryOptimizer.java
	phoenix-core/src/main/java/org/apache/phoenix/query/ConnectionQueryServicesImpl.java
	phoenix-core/src/main/java/org/apache/phoenix/schema/MetaDataClient.java
	phoenix-core/src/main/java/org/apache/phoenix/util/IndexUtil.java
Backport minor fixes from 4.0