Add ivy-info.

[Luis-Henriquez-Perez]

This is the initial pull request for adding ivy-info, an ivy equivalent of helm-info. There are probably many things that need to be changed for example perhaps you'd prefer it to be called counsel-info. Please let me know.

[abo-abo]

Thanks. It works for me. And the code isn't very long.

1. Please rename it to counsel-info and put it in counsel.el.
2. For changes over 15 lines you need an Emacs Copyright Assignment. See CONTRIBUTING.org for more info.
3. Looks like some code is copy pasted from somewhere. There's even a reference to issue #1503. Please clean up and rewrite the code so that we can put it in GNU ELPA.

[Luis-Henriquez-Perez]

I've done #1 and #3. Please let me know if there's sometime more you'd like.

I will now work on the commit assignment.

Oh and here's a question:

helm-info' has the side-effect of creating a function for each info node (ie. elisp-info, emacs-info, org-mode-info, etc.). I ported in to counsel` in such a way that this is no longer the case.

An argument could be made that this behavior is desirable. I suspect that like me most pople vast majority of the time only visit a handful of info nodes (elisp, emacs and org-mode). So perhaps it could be convenient to the specialized functions around. Wha t do you think?

[abo-abo]

I ported in to counsel in such a way that this is no longer the case.

Thanks. I like it this way more. The user can define a custom function in their config if they want. I'd rather keep the counsel namespace cleaner.