AARead.ORFs doesn't return all ORFs.

[bamueh]

In the the sequence SHVANSGYMGMTPRLGLESLLE*A*MIRVASQ, the AARead.ORFs function only returns the ORF GMTPRLGLESLLE but omits TPRLGLESLLE.

Here's a failing test:

def testTwoStartsOneStop(self):
    """
    A sequence with two start codons and one stop codon must return two
    orfs.
    """
    read = AARead('id', 'SHVANSGYMGMTPRLGLESLLE*A*MIRVASQ')
    orfs = list(read.ORFs(False))
    self.assertEqual(2, len(orfs))