improve mysql default settings

I think it's smart to set these PDO settings as default. This way you get the correct value types out of your database. I added two images with a var_dump() ouput after settings these options and before.

Before:
![before](https://cloud.githubusercontent.com/assets/5982785/2604576/d3be7eb8-bb3b-11e3-8e2d-9ef6cbf6cb45.png)

After:
![after](https://cloud.githubusercontent.com/assets/5982785/2604581/e1277b2c-bb3b-11e3-9fa6-3e644d421cda.png)

Take also note of the php documentation. It should be possible to use these settings with php 5.1 or greater.