HelpMojo class generated by helpmojo goal uses deprecated annotations

The helpmojo goal generates a HelpMojo class that uses 'expression' annotations on parameter fields rather than 'property' annotations. This results in a lots of output at warning level when building a plugin that uses the helpmojo goal for documentation.

This issue refers to javadoc/qdox style annotations generated by the maven-plugin-plugin 3.0 helpmojo. This version of the 'plugin' plugin does output Java 5 style annotations too but they are commented out.

Sample project attached. Running mvn package on the project will show the warnings.