[PROTOTYPE] Add jsdoc and use it as the plugin documentation

Adds configuration for https://github.com/pguedes/maven-jsduck plugin to generated jsdocs to the same path as enunciate would generate the documentation.

There seems to be no way to have two documentation links, so using enunciate and jsduck both needs some changes in core.

The maven-jsduck-plugin is not available from central, so you have to build it locally before trying this branch. The documentation of our js code is lacking at best, and is mostly not in a format recognized by jsduck.