Make state attribute in output ports human readable

[DarthBubi]

In the ruby version of rock-display the state attribute of an task was human readable, e.g. state: 0 equals state: INIT and so on. Especially, if a task has defined its own states it would be helpful to see the the state name instead of manually looking up the mapping of the enum value to a human readable one. Please add this feature back it would be an great enhancement.