7192275: Minimize LogManager dependencies on java.beans

[Alan Bateman]

I need a reviewer for a small change to the LogManager implementation 
that reduces its dependency on the beans classes.

As background, the LogManager addPropertyChangeListener and 
removePropertyChangeListener result in a toxic dependency on classes in 
the beans package. With modularity coming then I think we will 
eventually get to the point where we need to consider removing these 
methods, that's a discussion for another day. In the mean-time we need 
to minimize the dependency to only the PropertyChangeListener and 
PropertyChangeEvent classes.

The webrev with the change is here:
   http://cr.openjdk.java.net/~alanb/7192275/webrev/

The changes are very simple and just replace the code that was using 
PropertyChangeSupport (a supporting class) with a Map that is used to 
keep track of the registered listeners. One thing I found is that the 
tests in the jdk repository don't provide any coverage for these methods 
so I've used the opportunity to add a simple test to exercise this code.

Thanks,
Alan.