[FLINK-3093] Introduce annotations for interface stability in remaining modules

[rmetzger]

Please see #1426

This pull request depends on #1427

[aljoscha]

Should we also change names of stuff or open separate Jiras, PRs. I'm asking, for example, because of CheckpointNotifier which should be called CheckpointListener or something like it.

[aljoscha]

I created a patch of changes in the Stream API that I would propose:

stream-api-annotations.patch.txt

(you have to remove the .txt extension, github would not let me upload without it...)

[rmetzger]

Thank you for your patch. I've added it to the PR.

Regarding your question: I would keep name changes separate from this PR. Once this one is merged, we can start changing names.

Once #1427 is merged, I'll rebase this PR and we can finalize it.

[fhueske]

Created a PR for flink-java.

Summary

Changed to Experimental:

• DataSink.sortLocalOutput (should be deprecated, IMO. See FLINK-3186)
• DataSource.getSplitDataProperties
• SplitDataProperties
• DataSetUtils (not sure if we won't move methods out to core API, discussion please)

Changed to Public:

• CsvReader
• All subclasses of DataSet, incl. Operator
• Grouping and subclasses
• Either and EitherTypeInfo
• ObjectArrayTypeInfo
• FunctionAnnotation
• DiscardingOF
• TextIF and TextOF

[fhueske]

Do we want to make the IOFormats Public as well?
Most of them are hidden by helper methods of the ExecutionEnvironment. However, they can also be used as regular input formats via ExecutionEnvironment.createInput().

[rmetzger]

I merged both pull requests by @fhueske and the patch by @aljoscha and rebased the code on the lastest master (with flink-core annotations merged).

[fhueske]

Thanks for the update!
I'd like to do another pass over the DataSet Java and Scala classes next week.

[rmetzger]

Cool, thank you.
I'll rebase the PR, and go over the APIs again as well

[rmetzger]

I went through all the classes in the relevant modules outside flink-core with @fhueske and annotated them properly.
I've rebased the changes and checked with the additions in between.

I'm going to merge this PR in the next ~12 hours if nobody objects.