Add Code Completion for R

[saurfang]

Hi Jeff:

Here is my first attempt for #20. I had to upgrade ace library to 1.1.8 for some new features related to auto completion. I took the library from https://github.com/ajaxorg/ace-builds/tree/v1.1.8/src-min-noconflict. Hope this is okay for you.

For a quick summary, I have:

1. Updated aceEditor to take autoComplete to enable/disable code completion and autoCompleteList to take list of static code completion candidates. Again the latter is very useful for NSE functions as you can try in the demo below.
2. Updated updateAceEditor to allow enable/disable autocomplete and update static completion list.
3. Added aceAutocomplete to invoke utils:::.win32consoleCompletion which delivers the same code completions experience as R console.

The demo included in examples can be seen at: https://saurfang.shinyapps.io/shinyAceAutocomplete/

You can review this commit for all my code changes: saurfang@84d45db

Can you take a look and let me know if you have any questions or suggestions?

[trestletech]

This is really great stuff. Thanks for contributing.

I added you to the contributors list: https://github.com/trestletech/shinyAce#contributors-in-order-of-first-commit . Let me know if there's another URL you'd rather I link to.

Bumped to v0.2.0 with this feature. I'll let this soak on GitHub for a bit then push to CRAN.

[saurfang]

That looks great. Thanks a lot for taking my PR. I definitely like waiting for a bit to tease out any potential bugs.

[krdeepakio]

Is this feature live on CRAN or we need to get the package from github to use autocomplete?

[sjmgarnier]

@krdeepakio ShinyAce is still in version 0.1.0 on CRAN.