Fixed folder name  of yaml files in launch files
Merge pull request #1 from ethz-asl/fix/launch_files_config

Fixed folder name of yaml files in launch files (from etc to config)
Merge remote-tracking branch 'origin/master' into remake
Changed NodeImpl::advertiseService() with standard options to accept
a template argument of type Callback (to avoid future re-implementations
of the method for different overloaded callback signatures)