Add 9 fault injection cases in SS creation flow, and 5 of those
instantiate in the minimal examples ctests. The other 4 relate
to static policy and server, I tested the server ones by hand.
These tests confirm the recent change to unpick create using
lws_ss_destroy.
This adds an api allowing fault injection path implementations to get hold
of pseudo-random numbers between an externally-provided range.
You can set it using, eg, --fault-injection "f1(10%),f1_delay(123..456)"
while f1 shows how to decide whether to inject the fault and f1_delay
provides a pseudo-random number between the two values for the fault
implementation code to use.
