Re-enable SepReplicationSource tests for 0.98

Change the SepReplicationSourceTest to an integration test and
run it with a running HBase server. Due to changes in the
internals of HBase ReplicationSource in HBase 0.98, filtering can't
be tested in a fully-mocked environment.
Clean up in SepConsumer constructor

Remove lines of commented-out code around the SepConsumer
constructor for HBase 0.98.
Use Bytes.toBytes instead of String#getBytes

Use HBase library call for converting Strings to byte arrays to
ensure that a constant encoding (UTF-8) is used at all times.