adds check_path flag to cwe_checker for finding paths from user input functions to CWE hits.

This also fixes a bug in nested_exp_list, causing Load instructions to be added twice instead of once.

* Removes old version of log_utils, prototypes for new version.

* Implemented native logging

* Json-Output basically working.

* Added acceptance test for JSON parsing

* Adds some odoc to log_utils.

* Added support for file output (--cwe-checker-out)

* Add acceptance test for file output

Initial version of type inference. It is still very rudimentary at the moment since it just tracks pointer but it's a very solid start! 

* Initial version of Type inference