Merge pull request #1059 from tweise/hds

Fix invalid query result when key not present.
Fixing key de-serialization order of publisherId,advertizerId,adUnit
Merge branch 'hds' of github.com:Datatorrent/Malhar into hds
Merge pull request #1060 from sashadt/hds

Fixing key order to publisherId,adevertizerId,adUnit
Improve tests for HDSQueryOperator.
Change de-serialization from string encoding based on regular expression.
Test aggregation of tuples in unit test for QueryOperator.
Merge pull request #1061 from tushargosavi/hds

Improve tests for HDSQueryOperator.
Some cleanup.