Fixes FLINK-1276

Closes #229
[FLINK-1249] [APIs] [compiler] Add custom partitioner for CoGroup

This closes #228.
[FLINK-1221] Use only method name and location as default operator names
[FLINK-1221] Use StackTraceElement methods instead of String parsing

This closes #231.
Small changes and tests for the newly introduced EnumType

This closes #230.
[Java API] Fix various warnings
[FLINK-658] [APIs] Add group sorting to CoGroup

This closes #234
[runtime] Quick fix for error with unsupported ship strategy
[FLINK-1282] [docs] Update layout of docs

This closes #235.
[FLINK-1286] [APIs] [runtime] Fix serialization in CollectionInputFormat and generate meaningful error messages
[FLINK-1278] [runtime] (part 1) Remove special code paths for the Record data type in the input readers and the source task.
[Scala API] Case Class serializer can work with classes that cannot be instantiated empty
[FLINK-1282] [docs] Added {{ site.baseurl }} to css and image paths
[FLINK-1282] [docs] Make Flink logo link back to frontpage

This closes #237.
[FLINK-1234] Activate hadoop2 profile by default

This closes #232
[scala] Add ClosureCleaner for Scala Lambdas
[docs] Fix paths to work with local builds

Local builds of the docs without a web server (e.g. ./build_docs.sh -p)
were not working. This commit fixes this.
[runtime] CaseClassSerializer correctly treated as stateful
[scala] Fix slow building of adjacency list in Scala PageRank
Rewrite TPC-H Q3 to use Long instead of Integer

Both Java and Scala version fixed.