[PATCH] exec: fix ':' for stdin

Hi. I've found out that ':' for stdin in an exec pattern doesn't work. The reason is that if '!' is used for stdin, then the w_pty fd is just duped to the sub process, so that the p_pty is bypassed. But with ':' there is a relay mechanism via the p_pty. In order to match the behaviour of the bypas

split boundaries

Hi. On this screenshot http://upload.wikimedia.org/wikipedia/commons/b/b5/Gnuscreen.png one may see both horisontal and vertical white (blue) lines delimiting screen splits from each other. Mine doesn't show these: for example, text on both sides of a vertical splits is displayed without even a sp