Enable specifying the eg-iframe option in jsduck

Providing a custom eg-iframe is necessary in order to enable
live examples.

See https://github.com/senchalabs/jsduck/wiki/Inline-examples for why this is necessary. 

Note that this option already exists in jsduck and in the ruby options file, but was not being exposed in to the maven plugin. 

I followed the convention of using camelCase for the option in the xml.

I also bumped up the patch version number.

Sorry about making the pull request off master. I hadn't noticed that I was not on my topic branch until after pushing to github, and there is no easy way to undo that without causing a major headache.