run-tests: allow test output lines to be terminated with \r in addition to \n
str.splitlines could not be used in 546c76e5a3e6, but _now_ we would like to
have lines with other line endings than \n.
Some fine occurences of (esc) markup of \r is replaced with multiple lines
ending with '\r (no-eol) (esc)'. That is no win but also no significant loss.
This change makes it possible to drop filtercr.py - _that_ is a win.
[ original upstream message ]