Backporting of email 2.4 from Python 2.3. Many newly added modules,

Backporting of email 2.4 from Python 2.3.  Many newly added modules,
some updated modules, updated documentation, and updated tests.  Note
that Lib/test/regrtest.py added test_email_codecs to the expected
skips for all platforms.  Also note that test_email_codecs.py differs
slightly from its Python 2.3 counterpart due to the difference in
package location for TestSkipped.