Ruby 2.1.1 (continuation of #535)

Reboot of pull request #535, only updated to the current state of development for easier merging
please specify the mysql2 gem to version 0.3.14+; it looks like [some APIs changed in Ruby2](https://github.com/brianmario/mysql2/issues/365) and we need to update this gem (I had 0.3.13 installed by default for some reason).