First pass at a patch to only compile the new copy()
methods for (de)compression objects in zlib if the zlib
library supports them.

I ran autoheader to pick up the AC_DEFINE from
configure.in, and it looks like it changed
pyconfig.h.in quite a bit.  Probably the only part that
needs to stay in is the #undef ZLIB_HAS_COPY part.

If inflateCopy() is not found in the zlib library, then
the copy() methods are not compiled.

Lib/test_zlib.py has been updated to only test these
methods if they exist.