Allow RemoteUrlCommand based commands to work with non .com private repos

The first commit just replaces `git remote -v` and the ensuing loops/regex by using `git ls-remote`.

The second commit allows private repos with .net/.org etc. TLDs to work with this plugin.
+ I did think of using a different regex `\.(com|net|org|co\..{2}):` instead of replacing any occurences of `:`. See [here](http://rubular.com/r/3120b7qs44).
+ but that would be more complicated:
  + get the match
  + replace `:` in there with `/`
  + and then replace the original string (`repo_url`) again.
+ Since we are using `git remote -v` or `git ls-remote` we are guaranteed to get a sane URL. Hence replacing the `:` with `/` should be enough. So went with this approach, since YAGNI.

Let me know if you like the alternate URL implementation better.