Add regression test for #248 (already passes)
Generate Javadoc for the generated listener and visitor interfaces, classes, and methods
Add @NotNull annotations to listener and visitor methods
Merge pull request #258 from sharwell/generate-docs

Generate documentation for listener and visitor interfaces and classes
Fix unit tests now that the parser might not compute the conflicting alts BitSet before calling report methods
Merge branch 'master' of github.com:antlr/antlr4