Trying to use the repl features before newly started nodes have
riak_repl completely initialized leads to all sorts of nasty crashes and
noise. Frequently it makes fullsync stuck forever, which makes a lot of
the tests fail.
This also tweaks the AAE fullsync tests to remove assumptions about
failure stats when AAE transient errors occur. The behavior in the
handling of those errors has changed recently with the introduction of
soft exits.
Changed intercept to explicitly return `{error, econnrefused}`. Moved
helper functions to `repl_util` and added a new helper to distinguish
between disconnects on `cluster_by_name` and `cluster_by_address`
connections.
Added asserts to all wait_for functions.
