Allow local 'manager' component to be used to configure scripts

Currently scripts can be injected at VM startup or using the listener port.

To add greater flexibility, and allow management solutions to communicate with the byteman retransformer via their preferred mechanism (and security), it would be useful to enable a local user defined 'manager' component to be configured.

For example, instead of defining the 'listener:true' argument, could instead provide 'manager:<classname>'.

Will be submitting a PR of the proposed approach for discussion/evaluation.