Correction to code documentation in:
- a Parser function.
- the README.md file
FIXED: asterisk substitution was wrong.

The asterisk char * is not substituted with \ast{}, anywhere there is one.
The asterisk in the \begin and \end of LaTeX environs are treated
 corretly(think of \begin{equation*}).
Merge pull request #7 from alvarin32/master

FIXED BUG: asterisk substitution