Add DKPro and DKPro TC

[logological]

Consider adding DKPro to the catch-all "Natural Language Processing" section. It's a popular, freely licensed, community-authored collection of (mostly Java) libraries and other resources for NLP. One of the DKPro projects, DKPro TC, would also fit nicely in the "Machine Learning" section.

I should disclose that I am one of the 30-odd DKPro developers. However, I believe the project is widely used outside its development community. The papers describing DKPro have over 200 citations in scientific literature.