Add nice APIs with Annotations around UML2 and JDT

[lofidewanto]

We need to make the access to the UML2 and JDT more smoothly by adding a "thin" layer API and Annotations around them, just like here:

https://code.google.com/p/jaxb-fluent-api-ext/wiki/Introduction

or here:

http://weblogs.java.net/blog/kohsuke/archive/2005/06/writing_a_plugi.html