Change config for module definitions.

[totherik]

Currently, middleware modules are specified like this:

{
   "custom": {
        "enabled": true,
        "priority": 30,
        "route": "/foo",
        "module": "./lib/middleware",
        "factoryMethod": "customMiddleware",
        "arguments": [ "foo", { "bar": "baz" } ]
    }
}

This issue proposes to switch to using strings for simple exported middleware, or objects
for including additional information:

{
   "custom": {
        "enabled": true,
        "priority": 30,
        "route": "/foo",
        "module": "./lib/middleware"
    }
}

{
   "custom": {
        "enabled": true,
        "priority": 30,
        "route": "/foo",
        "module":  {
            "name": "./lib/middleware",
            "method": "customMiddleware",
            "arguments": [ "foo", { "bar": "baz" } ]
        }
    }
}

[totherik]

This change is available in meddleware@1.x