Supplementary derivation for s3cmd, building from git HEAD.
s3cmd-1.5-pre-81e3842f7a: Use more precise naming convention.
s3cmd-1.5-pre-81e3842f7a: Use buildInputs, not propagatedBuildInputs.
Mark s3cmd-1.5-pre-81e3842f7a as low priority.
Revert "s3cmd-1.5-pre-81e3842f7a: Use buildInputs, not propagatedBuildInputs."

This reverts commit 01211ff333a8554a45fbf3147a6ac4e550523a59.
Upgrade zeromq and nanomsg
Org-mode 8.2.7 depends on texlive-cm-super.
Merge pull request #2970 from tailhook/nanomsg_and_zeromq

Upgrade zeromq and nanomsg
rsync: sha256 for the patch was updated
idris: provide boehmgc to compile with llvm backend
emacs-idris-mode: upgrade to 0.9.13.1
nginx: add echo module, fix aio on linux&freebsd
nixos/nginx: fix group and stateDir permissions

furthermore, I don't think adding nginx to systemPackages is of any use.
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