[AC] Adjust load-path depth for modules

[Stephen J. Turnbull]

Ville Skyttä writes:

 > > That's cause the search recurses now.
 > 
 > Towards away from the filesystem root, without caring about
 > directory names it recurses into?  Then I would understand :)

That's right.  Remember in the packages tree the structure is
lisp/$PACKAGE, and that's the kind of situation this code is designed
to handle.  Make "lisp" the search root, then recurse into directories
looking for loadables (auto-autoloads for the packages, lisp, modules).
If found, add to the appropriate load-path.