Option to force ports into the serial ports list.

Added the ability to force a device into the serial ports list by adding a new-line separated list of ports in ~/.replicatorg/ports

Implementation note:

The RXTX java serial library uses a native method to find devices in /dev that are enumerated as serial ports in the IOServices list.  This will leave out many serial devices, such as those created with socat.  

.getPortIdentifiers maintains a list of ports.  You can add to this list by calling .addPortName, however, if you call .getPortIdentifiers again, you'll blow away any ports you added.  Hence, you need to create the port using .addPortName at a point in the code just before it is used, because if .getPortIdentifiers is called again, you'll lose your new CommPortIdentifier.

Its kind of a hack, but works.