* (bug 13615) Update case mappings and normalization to Unicode 5.1.0

* (bug 13615) Update case mappings and normalization to Unicode 5.1.0
  Note that case mappings will only be used if mbstring extension is not present.

Normalization data files updated to Unicode 5.1.0; passes the automated tests.

Seem to have long since lost the script I originally used to generate the Utf8Case.php mapping file, which appears not to have been updated since 2002 or so. :)
Made a new one and moved it into the UtfNormal sub-library.

Note a couple limitations:
* Case mapping (still) uses only the 1:1 simple mappings. Any full or locale-specific mappings are ignored.
* These case mappings are not used anyway when the PHP mbstring extension is available; mbstring's case conversion functions are used instead, with whatever version of Unicode support and whatever complex mapping support they may or may not have.
* The generated Utf8Case.php file is not used directly -- you must also regenerate the serialized version in the 'serialized' directory after updating it to a new Unicode version.