(Variable Renaming) Rewrote makefile; fixed bug for edg4x

* Makefile uses list of input files from Cxx_tests/Makefile-pass.inc

* Makefile uses the ROSE Test Harness

* Fixed bug in VariableRenaming::insertDefsForExternalVariables()
  because it didn't take into account the fact that under edg4x
  the formal parameter names for a locally-declared function are
  in the global scope.  I.e., "x" in this input:
     void f() { void g(int x); }