haskell: add csv-conduit, packdeps

csv-conduit is a CSV library using conduit (streams)

packdeps is an executable to compare Haskell dependencies to latest
available versions
mp3gain: Add package

This adds mp3gain which is a normalizer for mp3 audio files.
Merge pull request #5402 from bergey/haskell-csv-conduit-packdeps

haskell: add csv-conduit, packdeps
Fix missing paths
Merge pull request #5412 from devhell/mp3gain

mp3gain: Add package
fix maintainer information
s/maintainer/maintainers
Fix license attribute of many bsd-like licensed packages