Discussion on ruby19 compatible

1. `jeweler` is completely not compatible with ruby19 cause it use rcov by default and rewrite gemspec file on every release workflow
2. You do not have to make backward compatible like jeweler does(It ever support Gem under 1.2?) Yeah~ It's nearly 2014
3. `require 'bundler/gem_tasks'` in your rake file and you will have some great tasks for build, install and release

Have a look at this: http://bundler.io/v1.3/rubygems.html

I'm still working on this branch, discussion is welcome

PS: and yes. these code is compatible with ruby19, but not the development gems.