That script recursively walks over all files in current directory
and put in each python file the copyright information which by 
default is got from ~/.copyright

If there is "copyright" or "author:" words in the file content when it is not
altered and the file name is displayed after all files are processed

Copyright is inserted as first as possible but after following items:

 * #! line
 # coding: vim directive
 * first docstring (module docstring)