- rename ext_normalise to ext_normalize
- move modules to from /usr/lib to /lib
- centralize make rules

branches: 1.1.2; 1.1.4; 1.1.8;
Add NPF "rndblock" extension to randomly drop packets (using a random function
with a percentage or modulo operation). This is a demo module, although it can
be used for packet loss simulation. Example of a procedure in npf.conf:

procedure "somedrop" {
# Drop 1.9% of the traffic
rndblock: percentage 1.9
}