fixed a bug that caused a wrong offset when parsing SCF files

fixed the error in the comments parser
added support for code set "2" (IUPAC)

Signed-off-by: Hannes Brandstätter-Müller <hannes.mueller@gmail.com>
Merge pull request #6 from brandstaetter/scf-offset-fix

fixed a bug that caused a wrong offset when parsing SCF files