Add extra jsdoc3 parameters

Hi,

I needed to pass some config to jsdoc3, so I needed the '`-c`' option.  These changes seem to work for me.

E.g. my `conf.json` uses an alternate template, and turns off output of source files ([pretty print](https://github.com/jsdoc3/jsdoc/issues/208#issuecomment-9621558)):

```
{
    "opts": {
        "template": "jsdoc/jsdoc3-templates/my_first_template",
        "templates": {
            "default": {
                "outputSourceFiles": false
            }
        }
    }
}
```

And my pom:

                    <configFile>jsdoc/conf.json</configFile>

Both the path to `conf.json` and the path to the template are relative to my `pom.xml`.