OPEN - task 3: Index-Maps 
http://github.com/markus1978/emf-fragments/issues/issue/3

added implementation of bounded indexed map iterators and tests for this
implementation.
OPEN - task 7: Indexed-maps with containment 
http://github.com/markus1978/emf-fragments/issues/issue/7

added functionality for Indexed-maps with containment.
added tests for Indexed-maps with containment.
updated fragmentation functionality accordingly.
updated `FragmentsBaseTestSuite`.