#43 MapHandler should keep existing topics

[Lars Heuer]

The MapHandler should assume that the older topic contains more information than the newer topic and merge the newer topic into the existent and remove the newer topic.
Check also if tinyTiM is also effected by this bug:
http://code.google.com/p/mappa/source/diff?spec=svn165&r=165&format=side&path=/mappa/trunk/tests/test_miohandler.py
and http://code.google.com/p/mappa/source/detail?r=164