Update prefs to Harmony r772995.

Update prefs to Harmony r772995.

Notable changes:
 - exception handling has changed to cleanup more reliably
 - calls to Collection.toArray() size the array properly
 - lots of style tweaks (rewrapping Javadoc, reintending wrapped code, whitespace)
 - new PrefsTester class ensures tests store prefs in the tmp directory

Squashed commit of the following:

    commit 2157269d8ed39ccb8a71d735c12bbabcfd548243
    Merge: d287282 97818bf
    Author: Jesse Wilson <jessewilson@google.com>
    Date:   Wed Aug 5 11:14:26 2009 -0700

        Merge branch 'prefs_772995' into prefs_dalvik

        Conflicts:
        	libcore/prefs/.classpath
        	libcore/prefs/.settings/org.eclipse.jdt.core.prefs
        	libcore/prefs/build.xml
        	libcore/prefs/make/exclude.linux.x86_64.drl
        	libcore/prefs/make/exclude.windows.x86.drl
        	libcore/prefs/make/exclude.windows.x86_64.drl
        	libcore/prefs/src/main/java/java/util/prefs/AbstractPreferences.java
        	libcore/prefs/src/main/java/java/util/prefs/BackingStoreException.java
        	libcore/prefs/src/main/java/java/util/prefs/FilePreferencesFactoryImpl.java
        	libcore/prefs/src/main/java/java/util/prefs/FilePreferencesImpl.java
        	libcore/prefs/src/main/java/java/util/prefs/InvalidPreferencesFormatException.java
        	libcore/prefs/src/main/java/java/util/prefs/NodeChangeEvent.java
        	libcore/prefs/src/main/java/java/util/prefs/NodeChangeListener.java
        	libcore/prefs/src/main/java/java/util/prefs/PreferenceChangeEvent.java
        	libcore/prefs/src/main/java/java/util/prefs/PreferenceChangeListener.java
        	libcore/prefs/src/main/java/java/util/prefs/Preferences.java
        	libcore/prefs/src/main/java/java/util/prefs/PreferencesFactory.java
        	libcore/prefs/src/main/java/java/util/prefs/RegistryPreferencesFactoryImpl.java
        	libcore/prefs/src/main/java/java/util/prefs/RegistryPreferencesImpl.java
        	libcore/prefs/src/main/java/java/util/prefs/XMLParser.java
        	libcore/prefs/src/main/java/org/apache/harmony/prefs/internal/nls/Messages.java
        	libcore/prefs/src/main/native/prefs/windows/PreferencesImpl.c
        	libcore/prefs/src/main/native/prefs/windows/hyprefs.rc
        	libcore/prefs/src/main/native/prefs/windows/makefile
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/AbstractPreferencesTest.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/AllTests.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/FilePreferencesImplTest.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/MockAbstractPreferences.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/MockPreferencesFactory.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/MockSecurityManager.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/NodeChangeListenerTest.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/PreferenceChangeListenerTest.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/PreferencesFactoryTest.java
        	libcore/prefs/src/test/java/org/apache/harmony/prefs/tests/java/util/prefs/PreferencesTest.java
        	libcore/prefs/src/test/java/tests/prefs/AllTests.java

    commit d287282b550d4a5d262f1d1703344ed61bdc6d15
    Author: Jesse Wilson <jessewilson@google.com>
    Date:   Tue Aug 4 14:36:36 2009 -0700

        Dalvik Prefs

    commit 97818bf21cfde744eeb5fbf1f9c31d9bd66f5a2e
    Author: Jesse Wilson <jessewilson@google.com>
    Date:   Tue Aug 4 14:35:52 2009 -0700

        Prefs 772995

    commit 9a506f93947938dad3b41e1393f53b766ba0319f
    Author: Jesse Wilson <jessewilson@google.com>
    Date:   Tue Aug 4 14:22:40 2009 -0700

        Prefs 527399