Merge pull request #38 from pwendell/dev

Correcting an error in the README
Fixed #39: Wrap all calls to object inspector factory with synchronized
lock to serialize the access to the static hash map for object inspector
cache.
Rewrote ScriptOperatorHelper in Scala.
Renamed shark.exec package to shark.execution. This is done mostly for
easier differentiation between Shark and Hive because Scala compiler
often only reports the last level package name, and it was hard to tell
hive's exec apart from shark's exec.
Updated shark-shell repl initialization code to work with the latest
Spark dev branch.
Renamed shark.exec to shark.execution in remaining files.
ADD FILE
style fixes.
Removed KeyWrapperFactory.java. As a side effect, moved
GroupByPre/PostOperator.scala into org.apache.hadoop.hive.ql.exec
package so we can access KeyWrapper abstract class, whose methods are
only visible to classes in that package.
Merge branch 'dev' of github.com:amplab/shark into dev
Adding jars to SparkContext
Some cleanups.
Disable Spark combiner for group by. Fixed #5.
Disable Spark combiner for group by. Fixed #5.
Merge branch 'dev' of github.com:amplab/shark into dev
Undo the last commit on shark-env.sh ...
Cache tables using 'TBLPROPERTIES ("shark.cache" = true)' flag
instead of '<table name>_cached' (#45). Also some cleanup.
Determine initial capacity for ArrayLists in Column.scala during runtime
and provide a config option for it (#43).

Changed String size to 16 byte constant for size estimations.
Added a null check for 'conf' in ColumnarSerDe.initialize() and a config
varible to toggle "_cached" checking.

Added logging and increased ArrayList initial sizes for serialized objects.
'import' formatting in Column.scala...