As requested per

http://groups.google.de/group/comp.lang.python/browse_thread/thread/6feadf8170900e53/aa621eed0fe14050?hl=de#aa621eed0fe14050

list.sort() should support extra keyword arguments
start and stop, which specify a slice of the whole list
to sort inplace.

The attached patch implements this functionality, and
extends the sorted() builtin to also offer these
keyword arguments, and additionally implements slice
support (also with start, stop) for list.reverse().

The patch updates the list object methods and the
sorted builtin, and also updates the testsuite to check
for the new keyword arguments and updates the
documentation to list them.