Rework permissive autolinks.

 * We have now dedicated run over the inline marks for them.

 * We check more throughly whether it really looks as an URL or e-mail
   address. The old implementation recognized even heavily broken ones.

 * This allows us to be much more careful in order not to cross already
   resolved marks.

 * Share substantial parts of the code between all three types of the
   permissive autolinks (URL, WWW, e-mail).

 * Merge their tests into one file, spec-permissive-autolinks.txt.

 * Add one pathological case which triggered quadratic behavior in the
   old implementation.

scripts/run-tests.sh

@@ -31,16 +31,8 @@ echo "CommonMark specification:"
 $PYTHON "$TEST_DIR/run-testsuite.py" -s "$TEST_DIR/spec.txt" -p "$PROGRAM"
 
 echo
-echo "Permissive e-mail autolinks extension:"
-$PYTHON "$TEST_DIR/run-testsuite.py" -s "$TEST_DIR/spec-permissive-email-autolinks.txt" -p "$PROGRAM"
-
-echo
-echo "Permissive URL autolinks extension:"
-$PYTHON "$TEST_DIR/run-testsuite.py" -s "$TEST_DIR/spec-permissive-url-autolinks.txt" -p "$PROGRAM"
-
-echo
-echo "WWW autolinks extension:"
-$PYTHON "$TEST_DIR/run-testsuite.py" -s "$TEST_DIR/spec-permissive-www-autolinks.txt" -p "$PROGRAM"
+echo "Permissive autolink extensions:"
+$PYTHON "$TEST_DIR/run-testsuite.py" -s "$TEST_DIR/spec-permissive-autolinks.txt" -p "$PROGRAM"
 
 echo
 echo "Hard soft breaks extension:"