Migrating to Jenkins 1.500 break JDK5 compatibility - UnsupportedClassVersionError: Bad version number in .class file

The upgrade of the Commons Codec lib from 1.4 to 1.7 with Jenkins 1.500 break the compatibility to build with JDK5.

The build fails with

[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to load org.apache.commons.codec.DecoderException
Bad version number in .class file
[INFO] ------------------------------------------------------------------------
[INFO] Trace
java.lang.ClassFormatError: Failed to load org.apache.commons.codec.DecoderException
at hudson.remoting.RemoteClassLoader.loadClassFile(RemoteClassLoader.java:193)
at hudson.remoting.RemoteClassLoader.findClass(RemoteClassLoader.java:144)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.Thread.run(Thread.java:595)
...
Caused by: java.lang.UnsupportedClassVersionError: Bad version number in .class file
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
at java.lang.ClassLoader.defineClass(ClassLoader.java:466)
at hudson.remoting.RemoteClassLoader.loadClassFile(RemoteClassLoader.java:191)

Replacing Commons Codec 1.7 with 1.6 seems to fix the problem.
On the Commons Codec site (http://commons.apache.org/codec/) the following compatibility notes can be found:

Codec 1.7 requires Java 1.6
Codec 1.6 requires Java 1.5
Codec 1.5 requires Java 1.4

So please downgrade to Commons Codec 1.6 if possible.