* remove sed for cgi, cgi is deprecated and about to be dropped
* remove CPPFLAGS/LDFLAGS. it leaks into sysconfig and builds fine without it
* don't set CXX (defaults to g++ otherwise). nure sure why an absolute path is
needed here and not for CC. It builds fine without it.
* remove ac_cv_func_bind_textdomain_codeset override, gets detected correctly
* drop LC_CTYPE, we default to utf-8
* remove EXTRA_CFLAGS, cpython supports CFLAGS since forever
* remove some optdepends commented code
c7e102a61a