Issue #205 - refactor test code so that runReplication() can be called from any test

https://github.com/couchbase/couchbase-lite-android/issues/205
Issue #205 - Test to detect that Replications are not being removed from _active_tasks (REST api)

https://github.com/couchbase/couchbase-lite-android/issues/205
Issue #205 - the tests now wait until replications are removed from _active_tasks (REST api)

https://github.com/couchbase/couchbase-lite-android/issues/205
Update submodule
update submodule