Migration kit for converting the filesystem structure from file.py to docfile.py. Docfile.py filesystem structure is a stricter subset of file.py filesystem. Extensions of files are all lower case. Files are all named after the corresponding bibdoc. Thus there can't exist more than one file with the same format and version for the same bibdoc. The script take care of creating a bibdoc with a similar name in order to host the conflicting bibdoc.