copy, pop, get, getitem, setdefault
Also add read steps to taint tracking.
Reading from a tainted collection can be done in two situations:
1. There is an acces path
In this case a read step (possibly from a flow summary)
gives rise to a taint step.
2. There is no access path
In this case an explicit taint step (possibly via a flow
summary) should exist.
The current PAM auth bypass query which was contributed by me a few months back, alert on a vulenrable function but does not check if the function is actually function. This leads to a lot of fasle positives.
With this PR, I add a taint-tracking configuration to check if the username parameter can actually be supplied by an attacker.
This should bring the FP's significantly down.
