Reimplement equals and override hashCode to match equals
removed empty plugin.xml
Specified the 1.5 SE as execution environment
Updated source build
Add an EntityResolver that handles namespace verification. The choosen implementation rilies on the fact, that the input data is well formed and must not be validated in a time costly manner. This concludes the most pressuing issue of #5.
Revert to the previous version where DTD was defined.
The database product is always needed when the input method is not without DB. This concludes #24.
