Added PactAssembler skeleton.
Merge remote-tracking branch 'remotes/prze/master'
Code cleaned up
added PactGeometry value
Implemented the NodesReducer
merged bjoern's branch
chnaged PactGeometry value
Merge https://github.com/bjoernlohrmann/stratosphere-workshop-template
The InputFormat uses the PactGeometry value now.
Made the NodesReducer more efficient by removing an unnecessary list.