Don't store the Gemfile.lock
Remove version requirements on dev dependencies
Convert README to markdown and update content

Will be getting rid of the site, we'll let Github and rdoc.info do the
documentation hosting for us.
Update year on the license
Remove rdoc generation from Rakefile
Update gemspec, remove dev dependency
Update README to show more about how to use distance calculations
Show supported CLI services in the help
Fix double-escape issue with Mapquest API urls