packed-seq 4.0.0

New features

• Add BitSeq and BitSeqVec as 1-bit encoded 'sequences' that by default indicate the positions of ambiguous (non-ACTG) characters.
• Add BitSeq::par_iter_kmer_ambiguity that returns for each kmer whether it contains an ambiguous base.

This is used in simd-minimizers to only return minimizers of windows that do not contain ambiguous bases.

Breaking changes

• Encapsulate parallel iterators in new PaddedIt { it, padding: usize } type with .map, .advance, zip, and .collect_into functions.
• Make delay passed into par_iter_bp_delayed a strong type Delay(pub usize) to reduce potential for bugs.