Android API bugfix in equals

Signed-off-by: Johannes Morgenroth <morgenroth@ibr.cs.tu-bs.de>
daemon: Activate sequencenumber checking in LOWPANDatagramService
daemon: Add unittest for DatagramConvergenceLayer
Improve discovery test for DatagramConvergenceLayer
daemon: Add queue test for DatagramConvergenceLayer
ibrdtn: Use specialized exception if a entry is not found in the Dictionary