Add forgotten transition header for interiornodeconstraints.hh.
Replace deprecated GenericReference* by Reference*.
Add space between >> from templates because older compilers dislike that.
Merge branch 'p/gruenich/fixes'

Some fixes from Christoph. Thank you!

* p/gruenich/fixes:
  Add space between >> from templates because older compilers dislike that.
  Replace deprecated GenericReference* by Reference*.
  Add forgotten transition header for interiornodeconstraints.hh.