Fix dialyzer warning handling

The dialyzer warning file can't have a blank line, or this will match
_all_ warnings. tools.mk has been updated to check for this, and I've
removed the offending line from the Riak CS dialyzer ignore file.
Remove unused dialyzer replication ignore file

This was used if you did not have the closed-source replication modules
installed, but tools.mk does not yet (if ever?) have support for this.