Make autocomplete compatible with shiny modules

[GregorDeCillia]

Attempt to resolve issue #49

[vnijs]

Thanks @GregorDeCillia. Although I think that autocompletion inshinyAce should support modules, I am concerned about possibly breaking others' applications if we change the default structure of the input string used. I'd much rather do something like add an additional argument to aceAutocomplete. I'm cc-ing @saurfang since he is the expert on the autocomplete functionality in shinyAce in case he has additional ideas.

Honestly, I still don't see why modules don't work here if all they do is change "editor" to "sessiona_editor" as that should just be the new inputId. Perhaps I'm missing something.

[saurfang]

I was able to verify this fix. It looks Shiny makes assumption that all inputs belonging to a module share the module id prefix. If we list input names inside module server function, we only get list of inputs that have the module prefix with their prefix already stripped out.

While I think there is way to make this fix backwards compatible but it would be too complicated for it to be worthwhile. (i.e. we pass along namespace prefix into the widget and reconstruct the current hint input naming convention.)

I'm supportive of this breaking change since I suspect very few people use shinyAce_inputid_hint explicitly. Can you add this breaking change in NEWS.md (and maybe bump the version?)