pkas
Added a 'protein-charge' function for calculating the charge of a protein.
Added lower case letters to the sequence hashes to save time during sequence processing
Streamlined 'clean-sequence'
Added bigseq namespace for analysing files with very large sequences, i.e. chromosomes and genome
Cleaning up code
Merge branch 'bigseq' to get some improvements in core an alphabet.
Removed bigseq for now