my-env: Preserve http_proxy and ftp_proxy variables

There are few build scripts which set them to `nodtd.invalid` to disable
downloading files by buildscript. But for user environment we should
restore original values
pinfo: resurrect, update, add meta
update dd_rescue
Update eigen
Adding vpnc configuration module
Oops; a mistake with src
Revert "Revert "Merge pull request #3182 from wkennington/master.ipv6""

This reverts commit ea8910652fcecbcd4f21aa1c66b1a0a239408b04.
Revert "Revert "Fix syntax error in nixos/lib/build-vms.nix, introduced by 86c0f8c""

This reverts commit 2f697bf6931b24cdd428e22effbf6427a85afd42.
nixos/network-interfaces: Fix bug in converting old ipAddresses
cleanup per Lethalman's suggestions
Update and adopt LVM2.
haskell-directory-layout: 0.7.4 -> 0.7.4.1, doCheck = true
Enable dmeventd
Update dmraid
Merge pull request #3904 from sfultong/vpnc-upstream

Adding vpnc configuration module
haskell-wordexp: add 0.2.0.0
pythonPackages.rainbowstream: 0.9.3 -> 0.9.5, fix build on py3k
agda-stdlib: update to 0.8.1

This is necessary after the Agda-2.4.2 bump
Update FPC binary expression
Update FPC to 2.6.4