Missing package private information in the AST with current master

[thunterdb]

I was trying to pick up on @mengxr 's branch [1], but I noticed that the current master does not give information about package private classes anymore (except for trait).

From the tests: symbol: PPrivate -> missing symbol: Private -> missing symbol: PProtected -> missing symbol: PTrait modifiers: it

This information was obtained from https://github.com/thunterdb/genjavadoc/tree/missing-info by running sbt test

[1] https://github.com/typesafehub/genjavadoc/pull/47