Classes are not visible in depending Plugins

The classes (e.g. ParentPageHandler) are not visible in dependent plugins (e.g. index-space). Even if they are exported and imported in the atlassian-plugin.xml.

This makes the projectdoc-plugin-api project useless. The documentation is misleading as long as we cannot explain how to make the classes visible.

The Doctype class is visible from within the code. Maybe this is only a visibility problem with spring/osgi?