Avoid `;` comments in column 0 since these are
supposed to be indented to `indent-column`.
Use `defface` rather than `make-face`.  Don't step on other namespaces.
Etc..

* caml-font-old.el: Fix the `provide`.
(caml-font-stop-face): Rename from `Stop` and use `defface`.
(font-lock-stop-face): Mark as obsolete.
(caml-font-lock-keywords): Refer to the faces directly, not to the vars
holding the face name.  Use \_< and \_> to match identifier boundaries
so we don't need to change the syntax-table's `_` to `w`.
(inferior-caml-font-lock-keywords): Idem.
(caml-mode-font-hook, inferior-caml-mode-font-hook):
`global-font-lock-mode` is always defined now.
Set `font-lock-keywords-only` via `font-lock-keywords`.
Don't set the `font-lock-syntax-table` any more.
(caml-quote-char): Delete variable.  Require `caml` instead.

* caml-font.el: Avoid `;` comments in column 0 since these are
supposed to be indented to `indent-column`.
(caml-font-stop-face, caml-font-doccomment-face):
Use `defface` to define the face.  Mark the variable as obsolete.
(caml-font-lock-keywords): Refer to the faces directly, not to the vars
holding the face name.  Use \_< and \_> to match identifier boundaries
so we don't need to change the syntax-table's `_` to `w`.

* caml-help.el (ocaml-link-activate): Use `with-silent-modifications`.

* camldebug.el (camldebug-overlay-event, camldebug-overlay-under):
Always define as an overlay.
(camldebug-event-marker): Always define as a marker.
(camldebug-event, camldebug-underline): Use `defface` to define them.
(camldebug-remove-current-event): Disable both the overlays and the
overlay-arrow, in case `window-system` changed since they were set.
(camldebug-set-current-event): Set `overlay-arrow-position` buffer-locally.