Broken links in java.awt.Toolkit's javadoc

We shouldn't ship jdk7 with broken links in the javadoc.

As of jdk7-b143, javadoc emits the following warnings:

../../src/share/classes/java/awt/Toolkit.java:1871: warning - Tag @link: reference not found: PropertyChangeListenerProxy
../../src/share/classes/java/awt/Toolkit.java:1889: warning - Tag @link: reference not found: PropertyChangeListenerProxy
../../src/share/classes/java/awt/Toolkit.java:1906: warning - @ is an unknown tag.

This appears to be a regression caused by this change:

http://hg.openjdk.java.net/jdk7/jdk7/jdk/rev/16f52939fa41