mail(1) misses addresses when replying to all

There's a parsing error for fields where addresses are not separated by
space. This is often produced by MS Outlook, eg.:
Cc: <foo@bar.com>,"Mr Foo" <foo@baz.com>

The following line now splits into the right tokens:
Cc: f@b.com,z@y.de, <a@a.de>,<c@c.de>, "foo" <foo>,"bar" <bar>

PR:		bin/131861
Submitted by:	Pete French <petefrench at ticketswitch.com>
Tested by:	Pete French
Reviewed by:	mikeh
MFC after:	2 weeks

usr.bin/mail/util.c

@@ -496,10 +496,11 @@ skin(name)
 				*cp2++ = ' ';
 			}
 			*cp2++ = c;
-			if (c == ',' && *cp == ' ' && !gotlt) {
+			if (c == ',' && !gotlt &&
+			    (*cp == ' ' || *cp == '"' || *cp == '<')) {
 				*cp2++ = ' ';
-				while (*++cp == ' ')
-					;
+				while (*cp == ' ')
+					cp++;
 				lastsp = 0;
 				bufend = cp2;
 			}