Merge pull request #181 from mikelj/master

Multilevel Anticaching Migration Modifications
Cleaned up HStoreConf parameter names. This might break code that was using 'client.table_stats_periodically'
**Major bug fix for @huanchenz**
The EE was not keeping track of IndexStats properly because we were using the catalog object's relativeIndex parameter.
Well, this parameter is not globally unique, so shit was getting overwritten. It was a real bummer.
So now we compute a composite id in the EE for each unique table+index pair. That ensures that we can get set things properly.

Ok, so I think I'm going to head back up to the Sex House for dinner with my ex-girlfriend. We're having lasagna.
Two fixes:

(1) The Array index type now properly keeps track of the number of entries that it has.
(2) Updated the TestStatsSuite to now check that INDEX stats returns the proper count per index per partition
Expanded TestStatsSuite to add new test case to check for index entry counts after deleting tuples
Merge remote branch 'upstream/master'