This is a huge commit:

(a) UDG Creation has been rewritten to allow better handling of
pointers and arrays in the future.

(b) A test infrastructure for UDG/DDG/DDGPatching has been created +
unit tests.

(c) The DDGPatcher now also updates the UDG because that is the only
way we can reliably patch more than one source. It has been renamed to
ArgumentTainter accordingly.

(d) A test infrastructure for joernSteps has been setup.

This commit breaks some steps used by paddingCopyToUser as they rely
on USE/DEF links from AST nodes to symbols, which have been removed. I
will add them again for convenience in one of the next commits.
USE/DEF links from AST-nodes are also installed again for convenience.
Test for DEFs from parameters.