handle multiple javadocs about javadoc-reader HOT 1 OPEN

Perhaps a little "add" link/button just below the choice of javadoc would be 
nice.
Clicking on this would just add another line with the same drop-down combo menu 
to
select a second javadoc set. This could function quite similarly to the 
add/remove
links for adding extra attachments when composing a gmail message.

Care must be taken for adding this feature. Issues with the same class being in 
two
javadoc sets, efficiency, most used ranking between two sets, etc., could all
negatively affect the usage experience.