argparse + optional dropping for 'N's
deleted unused lines, made n's lowercased, and fixed pep8 fomatting
Merge pull request #426 from ged-lab/fix/fastq-to-fasta_N

added dropping N counts #395
Merge branch 'master' into tests/file_exceptions
Merge branch 'master' into feature/missing_file_exceptions
removed highmem attr from truncated file load test
minor cleanup of _khmermodule: use Py_RETURN_NONE
added test for nonexistent file
merged properly with tests
clean up poential free of unallocated objects
added printout of error messages to file tests in test_counting_hash
cleanup of counting hash load function
added hashbits file loading tests
Merge branch 'tests/file_exceptions' into feature/missing_file_exceptions
added better exception handling to load hashbits function