rsync: sha256 for the patch was updated
libid3tag: apply fixes before build

Amongst other things, this stops things like mpd spinning up to full
memory when updating the database.
mpd: clean up some flags

Some changed, some are no longer used.
haskell-STMonadTrans: new expression
haskell-equivalence: new expression
haskell-free-operational: new expression
haskell-boxes: new expression
Agda: add 2.4.0.1, 2.3.2.2 is still the default for now
Merge pull request #2972 from proger/rsync-patch-hash

rsync: sha256 for the patch was updated
agda-stdlib: upgrade to 0.8 (they keep changing the version scheme)

Conflicts:
	pkgs/development/compilers/agda/stdlib-0.8.nix
	pkgs/top-level/haskell-packages.nix