This should match more economically and in line with marked
recomendations as well as not allow whitespace ( \s ) at the beginning
or end of a sub or superscript mark. Additionally, a failure in having
mixed sub and supers on the same line was corrected.
Uses ^^ for superscript and ^^^ subscript as wrappers in the same
pattern as italics and bold ( * and **, respectively)
Adds editor hot-keys and sytax highlighting. (CTRL-6/CTRL-7)
Exact values may not be ideal. Short of the suggestted overloading of ~,
I didn't see a better option for the delimiter.
David Bolack