Fixes data-constraint error when inserting lorem ipsum stuff

This patch fixes an error I just encountered when trying to add dummy content on a fresh bolt-installation (might be related to #782 )

![screenshot 2013-12-21 03 39 02](https://f.cloud.github.com/assets/1737019/1795109/1df7997c-69ea-11e3-94f0-38cce9d5f21f.png)

Clearly, mySQL doesn't like that "" is set as the value for `checkbox`, it expects an int (of type TINYINT). I'm running the latest mySQL build and just encountered a very similar error on a different project that I've never had before. My guess is that at some point MySQL introduced stricter handling of datatypes. Any inputs on this topic?