A number of new features

- Fixed support for templating (more to come from @nosami on that, and requires a new version of the server).
- omnisharp-helm-find-usages now supports follow-mode properly, with line highlighting. And it's more robust and less code.
- New omnisharp-helm-find-symbols.

Will add some gifs in the future...
It might be more idiomatic to do (if omnisharp-company-do-template-completion ..),
but I don't think this needs to be changed.