Moves Version class out of version.rb

The gemspec reads lib/version.rb at install time.  Version.rb require'd run_loop/version which meant that run-loop needed to be installed _before_ the gemspec could be resolved and the gem installed.

I decided to create a `deprecated.rb` for APIs to live in before they are removed.  There are large number of deprecations coming soon.

- [ ] @krukow Have a look.  No rush.  We will need to resolve this before the next release.