Support for Eclipse Kepler

As Eclispe Release train is on track and Eclipse Kepler will be released on 26/06/2013 I have prepared a pull request for support of the Activiti Designer in Kepler. 

Summary of the change:
Due to mandatory update of Graphiti to 0.10.0 minor API changes had to be adapted. The adaptions have been made with less refactoring as possible.

I made two commits:
- 'project import on Kepler RC3' contains changes, that happen during project import in Eclipse Kepler. You might want to omit these changes. 
- 'update to graphiti 0.10.0 for Eclipse Kepler' contains all relevant Graphiti API adaptions.