Remove suport for "configuration" classes

[lburgazzoli]

As today, the runtime supports loading configuration classes written in Java so as example:

class MyBeans {
    @BindToRegistry
    Processor myProcessor() {
        return ...;
    }
}

Those kind of classes may be sometime useful but given that we want to focus on the routes and that if needed such classes can be provided by a jar and referenced through camel-main's configuration properties, I'm proposing to drop them which has the nice side effect to dramatically simplify the code and allow to contribute the source loading mechanics to Camel.

Using @BindToRegistry and other annotations will of course be possible on RouteBuilder classes.

[lburgazzoli]

@nicolaferraro @davsclaus what do you think ?

[davsclaus]

Fine with me, less special camel-k then maybe better