Closes #114: Don't list normal dependencies as contrib dependencies

* contrib/slime-hyperdoc.el (slime-hyperdoc): Remove :slime-dependencies
on emacs libraries, these should be loaded via a simple require.

* contrib/slime-tramp.el (slime-tramp): idem for tramp.
Closes #112: Clarify use of slime-load-hook, don't use eval-after-load

* slime-autoloads.el (slime): Don't use `eval-after-load'.

* slime.el: Call `slime-setup' at the end.

* doc/slime.texi (Installation): Make the autoload recipe the
default recipe.
(Basic customization): New subsection. Mention `slime-load-hook`
and techniques for customizing keymaps.