Message2554

A patch for the itertools module in 2.3. The test coverage for the module is quite extensive, so I feel pretty confident that it works "as designed". One test fails, but this is a test of an implementation detail i CPython (reusing tuples). This is my first module port, so some things may not be "optimal" when it comes to the usage of internal Jython APIs. Feedback is very welcome. Oh, and I've actually never used svn before, so my file properties may be a bit off... 

'Henrik