Auto-generate API docs / highlight API classes

[Cervator]

With the new @API annotation @immortius introduced for API classes usable from moduels we might be able to flag those classes as special either in the Javadoc and/or by highlighting those on an API Doc page on the GitHub wiki (linking to the Javadoc per class)

If we really want to go crazy some sort of review process could detect changes to API classes to verify SemVer as accurate (not full auto there, but mark for review)

[immortius]

Note that @API is both a package and type annotation, and I'm generally applying it to packages.

[Cervator]

Linking to MovingBlocks/TerasologyLauncher#273

Likely we'll need to publish to a gh-pages branch to generate a GitHub page. Wiki isn't a good home for static documentation, although is great for linking intelligently from tutorial pages to related Javadoc