Changes:
* configure.in: Restore netbsd on mips, mipsel, mipseb.
* make-dist
(nextstep/Cocoa/Emacs.base/Contents/Resources/preferences.nib)
(nextstep/GNUstep/Emacs.base/Resources/preferences.gorm):
No longer make links.
* make-dist (tempdir): Don't create directories preferences.gorm
and preferences.nib, they are no longer required.
* configure.in: Delete mac-fix-env target, which has been
removed (Bug#3531).
