Ability to provide default Javadoc for J2SE Platform.
The instances registered in the "org-netbeans-api-java/platform/j2seplatform/defaultJavadocProviders"
folder are used to provide default Javadoc for J2SE Platforms which have no
Javadoc attached by an user. The J2SEPlatformDefaultJavadoc is also consulted
by the new java platform wizard when a new J2SE Platform is created to suggest
a Javadoc to a newly created platform.