internal: Improve handling of taxonomy term slugification. This paves the way to bring slugification options like transliteration to PieCrust. This change mostly makes sure we use one-way slugification, which means, for serving/previewing, we need to slugify each page's terms to compare to the stuff captured from the URL. It also simplifies things a bit in the code.

import os


def slashfix(path):
    if path is None:
        return None
    if isinstance(path, str):
        return path.replace('/', os.sep)
    fixed = []
    for p in path:
        fixed.append(p.replace('/', os.sep))
    return fixed