add-to-list examples need hook wrappers

[積丹尼 Dan Jacobson]

All such add-to-list examples:

     For instances where hosts keep obscure locations for paths for
     security reasons, manually add such paths to local ‘.emacs’ as
     shown below for TRAMP to use when connecting.

          (add-to-list 'tramp-remote-path "/usr/local/perl/bin")

need to be wrapped in hooks, or eval-after-load, else they will produce
errors when the user starts emacs.