Merge branch 'develop'

The ARA Algorithm does now support basic path finding. There is no route maintenance, failure handling or pheromone evaporation.
The OMNeT++ simulation does also work
Merge branch 'develop'
Updated the submodules to public addresses
Travis does no longer checkout the git submodules on its own
Fixed typo in git submodules
Fixed issues in the .travis.yml
Rewrote the aralib makefile. We do no longer need to generate Makefiles for that
Some more changes to the Makefiles to separate OMNeT++ builds from normal builds
Added clang to the Travis CI build matrix