restored mvn verify for travis
Merge pull request #21 from mleich/enableMvnVerify

restored mvn verify for travis
Reworked aggregations to allow combinable reducers
Fixed meteor tests with loaded packages
Fixed sopremo record layout bug when a key expression is VALUE
Fixed global enumeration for 0.4 ozone
Refactored global enumeration
Workaround for issue #244 of stratosphere
Fixed multi output operator serialization