python files dependency analysis:
  for "import local_python_module" statements
  for dependency on other files with open(filename) or other functions.
  for import of external dependencies and generate external depenencies.

- when doing batch processing we are not using multi core. What can we do about it?

- we need to cache the output of mass generators better. We didnt handle it up till now.
    lets take mkdocs in veltzer.github.io. It generates a whole folder and we need ot cache that folder
    and be honest about it.
    The abstraction:
    In checkers there is no output.
    In geneators the outputs are derived from the inpput (one to one)
    in mass geneatros which really should be called another name (creators) since they can create either:
      - a single files
      - several files
      - a whole folder
      - several folders
      - or any combination of the above
    And we should really know how to cache their outputs.
