Auto generate javadoc and add it to the website without releasing a new website version

[nbartels]

ATM the javadoc is copied from the current restfb release into the website project and everything is published.

We should find a solution to publish the javadoc without publishing a new website. So the restfb website and the javadoc are independent.

First idea: use a subdomain for the javadoc

[nbartels]

We can use javadoc.io to provide the javadoc. Only the deployment to maven central is necessary. As soon as the new version is propagated javadoc.io provides the new javadoc. Jump to older versions is possible, too.

http://www.javadoc.io/doc/com.restfb/restfb/