Replace doc references to load-hooks

Replace doc references to load-hooks

with-eval-after-load is a cleaner, standard feature that works
for every file
* doc/misc/calc.texi (Hooks):
* doc/misc/dired-x.texi (Installation)
(Optional Installation File At Point, Omitting Files in Dired)
(Omitting Examples, Find File At Point):
* doc/misc/ediff.texi (Hooks, Selective Browsing)
(Highlighting Difference Regions):
* doc/misc/efaq.texi (Disabling backups):
* doc/misc/gnus.texi (Startup Variables):
* doc/misc/idlwave.texi (Structure Tag Completion, Misc Options):
* doc/misc/org.texi (Handling Links):
* doc/misc/reftex.texi (Key Bindings, Keymaps and Hooks):
* doc/misc/sem-user.texi (Speedbar):
* doc/misc/speedbar.texi (Hooks, Minor Display Modes):
* doc/misc/viper.texi (Rudimentary Changes):
Replace load-hooks with with-eval-after-load