Auto-load safe-path and auto-load scripts-directory on Windows

[Eli Zaretskii]

I've noticed that the default values of these 2 path lists use ':' as
directory separator, even on MS-Windows.  Isn't that a bug?  (Does
anyone use these features on Windows? if so, how come no one noticed?)

Btw, the name of the variable "auto-load scripts-directory" is
misleading, as it really is a PATH-style list of directories, not a
single directory.