[riena-dev] ListenerList vs ArrayList

["Volanakis, Elias" <evolanakis@xxxxxxxxxxxxxx>]

Just FYI, in the Tree/Table/List-Ridget I changed the container for the
double click listeners to ArrayList (recently changed to ListenerList).
The reason for using an ArrayList is that adding duplicate listeners is
explicitly permitted there.

This fixes the recent test failures in #testAddDoubleClickListener. 

Feel free to discuss if you disagree. The alternative is to adjust the
tests / javadoc to disallow duplicate listeners.

Thanks,
Elias.