Revert "Temporarily removing the JUnit tests for the new parser. The new output of the parser don't match anymore."

This reverts commit 719be300a49df78b76c11575ac07b35f68bcf3c9.
Added a new test which replicates some ambiguities with lists and unary minus.
   - added back all the removed tests and fixed the helper methods to match the new TermCons output of the parser.
   - other small fixes.