silc_client: Missing file
silc_client: error in url

I should test better before push.
silc_client: more url problems

It was harder to test, after nix-prefetch-url. Damn it.
haskell-github: update to version 0.6.0
haskell-cabal-dev: update to version 0.9.2
git-annex: update to version 4.20130405