Consider allowing outside module names for light definitions

At present, its difficult to add light definitions without contributing directly to the project since the validate_item function assumes the PyDMXControl.profiles. module name being present. Perhaps the code could be modified si that if the module is not found you search the broader namespace for the module before failing.

I plan to hopefully contribute to this projects codebase on a few fronts after I get done with my own testing. 😄

In the meantime, I found a work around. If one defines a light in a file called MyLight with a class of MyAwesomeLight, they can add this to their executing class:

test.py

import sys
from PyDMXControl.controllers import OpenDMXController

import MyLight
sys.modules['PyDMXControl.profiles.MyLight'] = MyLight

dmx.json.load_config('light_config.json')

light_config.json

[
    {
        "type": "MyLight.MyAwesomeLight",
        "args": [],
        "name": "Light 1",
        "start_channel": 1
    },
    {
        "type": "MyLight.MyAwesomeLight",
        "args": [],
        "name": "Light 2",
        "start_channel": 8
    }
]

Start by tracing validate_item and the dmx.json.load_config entry point to see how the PyDMXControl.profiles. module is resolved. Define the fallback lookup behavior for externally defined modules, then verify that light_config.json entries such as MyLight.MyAwesomeLight load without the sys.modules workaround.