Improved the handling of errors and documentation of the functions in…

… scicm.tools

Added examples to the documentation of the three tool functions.

Fixed path issues in Windows

Pushed required setuptools version to 45.0.0

Now script works properly with tokens in .pypirc file

Added last colour map set

Fixed histogram scaling example

Fixed issue with tar.gz file for PyPI including all example images

Removed iso_3 and iso_4

Small fix to README