* Use valitydev/thrift compiler 0.14.2.3
* Bump to valitydev/dmt-core@7584133
* Bump to valitydev/machinegun-proto@a411c7d
* Drop repository v4
* Update to valitydev/dmt-client@ce6678a in tests
* Keep v5 migration code and tests as examples only
* Add testcase on `RepositoryClient`
* Add testcases on `Repository` functions exceptions
* Move unused msgpack protocol out to thrift runtime library
