applets_sh/*: Add a few more examples of "shell applets"

Signed-off-by: Pere Orga <gotrunks@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

applets_sh/dos2unix

@@ -0,0 +1,5 @@
+#!/bin/sh
+# TODO: use getopt to avoid parsing options as filenames,
+# and to support -- and --help
+[ $# -ne 0 ] && DASH_I=-i
+sed $DASH_I -e 's/\r$//' "$@"