Changed multi-line C comments into another style.

I changed _all_ comments whose left edge looked like
``` C
/* one
 * two
 * three
 * four
 */
```
into comments that look like
``` C
/* one
** two
** three
** four
*/
```

To my eyes, the old style looked unbalanced; and, the new style looks better.

(Now, we'll find out how many people dislike it. :smirk: )