Suggestion to cleanup editor instructions in python scripts

[miykael]

I'm preparing to cleanup the PEP8 violations mentioned under #2306 and encountered some other style issues in the text files.

1. Tailing spaces in a line and missing new lines at the end of files. Which should be taken care of with STY: deleting tailing spaces and adding missing newlines at end of files #2355.
2. Specifying editor variables (vi, emacs) such as here.
   Should we standardize them or delete them?
3. Is there a need for standardizing python files, so that they start either with #! (example) or with # -*- coding: utf-8 -*- (example).
   Or on the contrary, should those instructions be deleted?
4. Some scripts of the semtools and slicer interface, start with two lines of coding: utf8 instructions (example) and contain the phrase "Autogenerated file - DO NOT EDIT. If you spot a bug, please report it on the mailing list and/or change the generator." But I can only find for the slicer interface the file that generates those scripts.
   Should the utf8 instructions be deleted?