Update to use metafacture 2.0 and java 1.7

* add metafacture core to travis and pom
* add mysql connector to pom.xml
* close some potential leaks
`scanner`, `scanner1`, `scanner2` seems a bit messy to me. Couldn't we either use a single shared scanner that is reassigned, or always create a local scanner in the methods that use one (I think I'd prefer the latter).