Pre-release 0.4:sampalua persists, protocol requests can sup

actually I realized that as long as it remains structural modules, lua state doesn't need to persist, so there is no need to prevent from persisting!
a new scripts/sldemo.sh demontrates it
my longer term goal is still that on can fully develop a module with lua (then one will have to persist lua state which shall be possible as lper proves it).
Introduced new framework for protocol request: this permits to use extensions to the protocol requests even with existing compiled code!
tst/extensions demontrates this new capability.
done some fixes in calc_latencies and compare_traffic scripts (introduced a bug when using clock frequency in command line instead of clock period) so that they now give nice results...