[ ] test again on:
	- Linux (glibc+gcc, musl-gcc, clang, tcc).
	- OpenBSD
	- Windows (cygwin gcc, mingw).
[ ] test shellscripts with ubase/sbase tools.
	[ ] sfeed_update
	[ ] sfeed_opml_export
[ ] remove sfeed_stats ?
[ ] dogfood sfeed_frames, html content.
	[ ] in links browsers: items are centered in the table for some reason.
[ ] feeds file: empty tab (encoding can't be detected?)
[ ] optimize
	[ ] gettag() lookup.
	[ ] namedentitytostr lookup.
	[ ] xml parser, etc.
[ ] cleanup code.