Make the port number configurable.

[olofbokedal]

I need to do this since some hosts block communication on non standard ports, e.g. 10000. But Logentries supports various ports, so this is easily avoidable by making the port configurable.

• Removed the predefined constants.
• Removed property for DataHub port.
• Removed datahubPort argument from constructor.
• Added port argument to constructor.
• Return port property when calling getPort().

I'm not 100% sure about how the DataHub integration works, but this approach aims at keeping a single port for the entire instance by making it configurable via the constructor.

[StephenHynes7]

@olofjohansson sorry no one has looked at this sooner.

One thing I would like to see though is a default port to be used in case a user does not submit it. Ideally port 443 with SSL enabled.