getpw: Let's try "xte" instead of "xdotool"

Requires package "xautomation".

a) xte doesn't seem to require a delay after each key
b) In Firefox 25, special characters such as an "@" are sometimes broken
   with a xdotool
c) xte doesn't seem to require that hackaround
getpw: Don't beep anymore

xte sends text with no noticeable delay. I don't have to wait until it's
finished.
overqemu: Remove "-n"

It's a rare corner case and makes things complicated. When I really need
that, I can simply run QEMU directly.
overqemu: s/instance/slot

"Instance" suggests that it's one instance of a base image. But it's
not. It's actually one the 100 slots, no matter what the base image is.
overqemu: Add "-l" to list slotinfo
overqemu: Refuse to run on backing file mismatches
overqemu: Implement easy creation of multicast networks

This does the trick:

	$ overqemu -m 230.0.0.1:1234

"-m" can be specified multiple times.
overqemu: Revise comments
overqemu: Add "-cpu host"