Add Sanity Checks for Join/CoGroup with SolutionSet in Record API

We now check whether the key fields specified for the delta iterations
match those specified when joining/coGrouping with the solution set.
This code is more or less copied from the new Java API.

The Scala API uses the Record API underneath so it is also covered.
[FLINK-1047] Fixes main class for start-local.bat
[FLINK-1048] Swallow output of SET statements in ./bin/flink.bat
[FLINK-1051] ./bin/start-local.bat prints error message if java.exe cannot be found