Add interactionbtngroup example
Merge pull request #20 from fgravin/groupInteraction

Add groupinteraction example
Add generate-info.js
Add generate-exports.js
Add jsdoc config (required for generate-info.js)
Update build.js
Add jsdoc as a dependency
Build ngeo and ol together
"exports" required in build config
No longer need for specific compiler build
Remove the ol.js externs file
Update README