bug#62978: gnu: bpp-core, bpp-seq, bpp-phyl: Update to 2.4.1. && gnu: Add bpp-seq-omics, bpp-phyl-omics and maffilter.

[Ricardo Wurmus]

Thank you for these patches.  I applied them.

maffilter needed some changes:

- formatting
- license
- git-fetch vs url-fetch (can’t use generated archive URLs)
- sorting of inputs

-- 
Ricardo