Remove hive operators

Conflicts:
	src/main/scala/shark/execution/FileSinkOperator.scala
	src/main/scala/shark/execution/TableScanOperator.scala
	src/main/scala/shark/parse/SharkSemanticAnalyzer.scala
Update code according scala code style

Conflicts:
	src/main/scala/shark/parse/SharkSemanticAnalyzer.scala
Update code style
Account for removed `Operator.hiveOp` in FileSinkOperator.
Handle database namespaces for cached tables

Cached tables currently ignore database name which makes caching buggy for users using multiple databases.
Enhanced the memoryMetadataManager to require database name inaddition to the tablename for all metadata operations.

Conflicts:
	src/main/scala/shark/SharkEnv.scala
	src/main/scala/shark/execution/MemoryStoreSinkOperator.scala
	src/main/scala/shark/execution/SharkDDLTask.scala
	src/main/scala/shark/execution/TableScanOperator.scala
	src/main/scala/shark/memstore2/MemoryMetadataManager.scala
	src/main/scala/shark/parse/SharkDDLSemanticAnalyzer.scala
	src/main/scala/shark/parse/SharkSemanticAnalyzer.scala
	src/test/scala/shark/SQLSuite.scala
Patches for the 'database namespaces for cached tables' merge.
Account for database namespaces in tables created by RDDTable/RDDTableFunctions.
Add a method in SharkEnv to help with formatting table identifiers for RDDs stored in Tachyon.
Removed EmptyRDD given it is in Spark.
Merge pull request #201 from rxin/remove-emptyrdd

Removed EmptyRDD given it is in Spark.