Checksum fixes

Some packages failed to build on my Hydra with 404/checksum invalid errors. The patches update, modernize and fix checksums for a part of them. I've tried to build all of them; haven't run, though.
Oh, okay -- I'm fixing all packages that I touch like that after my discussion with @Fuuzetsu [here](https://github.com/abbradar/nixpkgs/commit/56473f683203ec0905f964f208125688afb8ebd3#commitcomment-8265884).