Merge pull request #4811 from jagajaga/steam

steam: update 1.0.0.48 -> 1.0.0.49
mpd: 0.19.1 -> 0.19.2
uhc: remove broken package

https://github.com/NixOS/nixpkgs/issues/3565
idea-{community,ultimate}: 13.1.5 -> 14pre
boost: Pass arguments to generic.nix
linux: Update testing 3.17-rc2 -> 3.18-rc3
Merge pull request #4770 from titanous/linux-testing

linux: Update testing 3.17-rc2 -> 3.18-rc3
ristretto: wrap icon theme
add elm-preprepl to package list
update picard 1.2->1.3
add elm-get to haskell packages
virtualbox: 4.3.16 -> 4.3.18
kdeconnect: upgrade from 0.7.2 to 0.7.3 add new dependency: libfakekey

libfakekey is an X virtual keyboard library
Update to hscope 0.4.1
threadscope: allow building with GHC 7.8.3, and on recent OS X
macvim: Update sha256
coq_HEAD: update to latest commit
Update Lazarus
Update Squid proxy
Update ioping