`rubocop-check-...` and `rubcop-autocorrect-...` commands don't work if the path contains spaces

[stormwatch]

The first argument passed to compilation-start ends up being somthing like:

bundle exec rubocop --format emacs /a/path/with spaces/something.rb

One solution would be to write quotation marks around the path:

bundle exec rubocop --format emacs "/a/path/with spaces/something.rb"

I am not sure about where to fix it, but probably involves wrapping some expresion inside shell-quote-argument.

Maybe here?

[stormwatch]

Probably related to #32