JDK 9 RFR of JDK-8042860 : Fix raw and unchecked warnings in java.beans

[Joe Darcy]

Hello,

Please review this draft fix for
    JDK-8042860 : Fix raw and unchecked warnings in java.beans
    http://cr.openjdk.java.net/~darcy/8042860.0/

Note that I did not try to generify the java.util.Collection methods in 
BeanContextSupport.

Thanks,

-Joe