new module that resume input parsers and output formaters

src/obitools/format/sequence/fasta.py

+from obitools.fasta import fastaIterator,fastaAAIterator,fastaNucIterator
+from obitools.fasta import formatFasta

src/obitools/format/sequence/genbank.py

+from obitools.seqdb.genbank.parser import genpepIterator,genbankIterator