Chanages to query secondary indices

Hello @x-ma, 

Please review the following commits I made in branch 'satya-secondaryIndex'.

f8d7e7badb897b6eb92a793aa11b09145245e056 (2013-10-31 15:02:01 -0700)
Support to query secondary index

Check list:


R=@x-ma
VISIBLE_CHANGES=Chanages to query secondary indices