Fix issue #1147, must encode dispatcher ID for etcd.
Fix for #1147 into CHANGELOG.
Merge branch '2.3' of ssh://github.com/triAGENS/ArangoDB into 2.3
Merge branch '2.3' of ssh://github.com/triAGENS/ArangoDB into 2.3
Merge branch '2.3' of ssh://github.com/triAGENS/ArangoDB into 2.3
Better error handling and cleanup if instanciation runs into error.

This concerns AQL in the cluster.