Minimize WindowsLookAndFeel classes included with Unix JDKs

Even though the WindowsLookAndFeel is not supported on Solaris, rt.jar for the latest (b96) solaris-sparc build contains 159 WindowsLookAndFeel-related classes, mostly in com/sun/java/swing/plaf/windows/. All this should be pared down to the minimum needed to be able to tell a Unix JDK that WindowsLookAndFeel.isLookAndFeelSupported() returns false.

The class comment for the src/solaris/classes/sun/awt/windows(?!)/ThemeReader.java states:
 * This is a stubbed out placeholder class, intended to allow building
 * WindowsLookAndFeel on Unix. This class is never actually called on
 * Unix, and will be deleted when WindowsLookAndFeel is no longer built
 * on Unix.

Let's do it. Removing these classes from Unix JDKs will decrease download size, and could potentially improve cold start time.