Cleanup the helper scripts

* Remove from __future__ import print_function, because we
  no longer support Python2.
* Clean out unused parts of tools/scripts/scriptCommon.py
* Move appveyorMergeCoverageScript to Python3
* Update user reporting in *release scripts
* Cleanup module imports

tools/scripts/fixWhitespace.py

@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-from  __future__ import  print_function
 import os
 from scriptCommon import catchPath