error handers in the Unicode codecs: Negative
positions are treated as being relative to the end of
the input and out of bounds positions result in an
IndexError.
Also update the PEP and include an explanation of
this in the documentation for codecs.register_error.
Fixes a small bug in iconv_codecs: if the position
from the callback is negative *add* it to the size
instead of substracting it.
From SF patch #677429.
for this iconv() implementation in the init function.
For encoding: use a byteswapped version of the input if
neccessary.
For decoding: byteswap every piece returned by iconv()
if neccessary (but not those pieces returned from the
callback)
Comment out test_sane() in the test script, because
whether this works depends on whether byte swapping
is neccessary or not (an on Py_UNICODE_SIZE)