Add support for dynamic_reconfigure

[mica-angeli]

The dynamic_reconfigure package uses service calls to provide a generic interface to change a node's parameters. Currently, a roslibjs client can interface to a node implementing dynamic_reconfigure using a service call (See dynamic_reconfigure/Reconfigure.srv).

However, it would be good to incorporate a Javascript API within roslibjs to interface with dynamic_reconfigure (similar to their Python API).

[mica-angeli]

I've created a tutorial wiki on how to currently use roslibjs as a dynamic_reconfigure client through service calls found here.