[FLINK-1173] [streaming] Add socket text stream as a data source for the streaming API
[FLINK-1173] [streaming] SocketTextStream minor fixes + documentation

This closes #204
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
deprecated current aggregation code
Test cases and API for new aggregations
ungrouped aggregations
grouped aggregations
missing license headers
moved AggregationUdf into correct package
name the aggregation operator in the DAG
additional tests for aggregation
CountAggregationFunction does not need an input type
documentation updates