Different strategy for raising and lowering scripts

[Christopher Dimech <dimech@gmx.com>]

I would like to try a different strategy for raising superscripts
and lowering subscripts.

Have copied the following customs and functions from "tex-mode.el".
Now I am struggling to write a function that enables the functionality.

In "tex-mode.el", the functionality is enabled as soon as one uses
the mode.  But I would like to enable things by calling an appropriate
function instead.

--------

(defcustom tex-fontify-script t)
(defcustom tex-font-script-display '(-0.2 0.2))
(defcustom tex-suscript-height-ratio 0.8)
(defcustom tex-suscript-height-minimum 0.0)
(defun tex-suscript-height height)

(defface superscript )
(defface subscript )

(defun tex-font-lock-match-suscript limit)
(defun tex-font-lock-suscript pos)
(defun tex-font-lock-unfontify-region beg end)