Added 'bootdelay' feature in boot monitor, it pauses a given number of ms

so the list of programs in the image and their sizes can be seen before the
kernel starts filling the screen.

Added some formatting fixes in installboot and boot monitor itself,
some of the segments were larger than the formatting allowed.

boot/boot.c

@@ -1549,6 +1549,7 @@ void help(void)
 		{ "ramimagedev",	"RAM disk image if root is RAM" },
 		{ "ramsize",		"RAM disk size" },
 		{ "bootdev",		"Special name for the boot device" },
+		{ "bootdelay",	        "Delay after loading, before booting (ms)" },
 		{ "fd0, d0p2, c0d0p1s0",	"Devices (as in /dev)" },
 		{ "image",		"Name of the kernel image" },
 		{ "main",		"Startup function" },