OPENDJ-1134 (CR-2355) Introduce a class in replication for encapsulating host+port combinations

Now the replication code uses HostPort class for comparisons instead of "host:port" Strings.
Changed all the HostPort variable/parameter names to *Address instead of *URL. Left all the relevant String variable/parameter names to *URL.


HostPort.java:
Removed LocalAddress(String), not used anymore.
Moved getLocalAddress() here from ReplicationServer.
Created localAddress() static method.
Extracted method toInetSocketAddress() and moved it here.

ReplicationServer.java:
Created converting method toHostPorts() + used it everywhere replicationServerUrls was accessed.
Replaced getNormalizedLocalURL() and normalizeServerURL() with simply calling HostPort.localAddress() and HostPort.valueOf().
In getConnectedRSUrls(), changed return type from Set<String> to Set<HostPort>.
In connect() and disconnectRemovedReplicationServers(), used HostPort as a parameter instead of String.

ReplicationServerDomain.java:
In stopReplicationServers(), used HostPort as a parameter instead of String.

ReplicationServerHandler.java:
Extracted method toServerAddressURL().

ReplicationBroker.java:
Consequence of the change to HostPort.


ReplSessionSecurity.java:
In isSslEncryption() removed unused parameter.
Used StaticUtils.close().

ReplicationServerConfiguration.xml, ReplicationServerCfgDefn.properties:
Added precisions on how to specify the "replication-server" property.

ReplicationServerDynamicConfTest.java, ReplServerFakeConfiguration.java:
Updated because this test was failing.