Remove unused logical def classes
Add travis configuration
Cherry-pick changes from jni_aggr/HACodeGenMaster

Cherry-pick more changes from jni_aggr/HACodeGenMaster.

Fix some issues and intermediate commit for hash aggregation.

Fix bug with hash table resizing, links update.  Modify template code generator for AggrType2 aggregate functions.  Add cleanup routine, do code cleanup.
Merge remote-tracking branch 'upstream/master' into aggr_branch
Merge branch 'aggr_branch' of https://github.com/amansinha100/incubator-drill into aggr_branch