Improve DC and InterDC Functionality (#408)

* Test case for issue #400 
* Removed stable riak metadata and improved create dc.
* Changed level of pending changes log messages
* Added a better named function to add nodes to a current dc
* Changed description and test case for dc descriptors. Fixed #400
* Reverted handle call for periodic updates, not needed
* Bumped to version 0.2.2
* Reduced severity of log message for missing external_descriptors
* Update include/antidote.hrl
* Added leave_dc functionality

We maintain our own dc id based on the riak_core_ring:cluster_name/1 command.
Riak maintains the cluster name itself, and contrary to the comment in dc_utilities,
it is restored on fail and restart correctly, even if all nodes fail at the same time.
This caused errors in maintaining the ring members after simplifying the create_dc function
and errors in shard count meta data. Switching back to the riak internal meta data
(which is managed and updated by riak_core anyway) fixes these issues.
The create_dc simplification also improved joining an empty cluster significantly (10 seconds for 8 shards).
This is also work towards being able to add/remove nodes dynamically to scale after some time elapsed.

Co-Authored-By: Peter Zeller <[email protected]>

Redirected slave logs to ct master logs

Cluster management pb fix (#372)

* downgrade lager because of logging problems
* change test setup

- forking ct_slave because it cannot be configured as I want it to
- now sets the working directory for slaves, so lager logs to the
correct directory
- standard output of slaves is written to the ct-log and to stio.log
file, which should make debugging easier
- protocol buffer process now also reports stacktrace to client
* also testing connect_to_dcs
* use different node names for cluster management test
* Adapted to cleanup of antidote_pc_codec
* Upgraded to lint v0.1.10 which is checking more things.
* Few fixes for the connection descriptors
* Encoding ignore in pb_client
* Updating the dependencies

fixed

Tag for hydra branch start