aqm-scripts: further cleanups to support mainline linux

Tedious bugs in the other scripts made me want to make
these the one and only scripts for testing on other
(eg x86) versions of linux.

So cleaned up code to run on ubuntu 13.4. All
you basically need to do is set:

INSMOD=modprobe
IFACE=eth0
QDISC=fq_codel

You still need to turn off gro, gso, tso on all
interfaces using something else like the debloat script.

Hopefully this doesn't break anything on openwrt.