implemented an interprocedural constant propagator to get rid of a certain class of false positives
fixed an NPE and a problem with taint wrappers. If a taint wrapper is used to generate artificial taints for a certain callee, we may not propagate the dummy values out of this callee since we don't know what the taint wrapper would have made out of it
fixed another NPE and started with removing methods that return constants and do not have side effects
using a separate icfg for code cleanup and taint propagation
now fixing the callgraph after removing units