installation-cd: add wget

[domenkozar]

wget adds 420K of additional space usage on minimal cd in exchange for comfort: everyone expects it to be there. Fixes #1489

[garbas]

@iElectric i guess we can close this PL and open others (for editors and subversion/git), right?

[domenkozar]

Sure, when @edolstra confirms subversion -> git switch is fine

[edolstra]

Subversion can definitely be removed. But I'm not sure if we should add Git, since it's quite a bit bigger than Subversion (20 MiB).

[domenkozar]

nix-store -qR /nix/store/5dmrca1pm536hn42qp6j4gw2sy1f0ww5-subversion-1.7.14|xargs du -shc is 285MB total

nix-store -qR /nix/store/rgs7fr1knh4m7mqw91ylgw169m4nalbh-git-1.8.5.2/|xargs du -shc is 406MB total

right.

[vcunat]

Only dependencies not included already are interesting, but that's more difficult to find out.

[domenkozar]

With git (minimal) and wget, removed subversion:

301M /nix/store/c4654l0n5vpnahf1qi0gwgkrkl5iyzd1-iso9660-image/iso/nixos-minimal-14.02pre5678.gfedcba-x86_64-linux.iso

Current iso with subversion:

278M /nix/store/vza1mmw8dlayc2s25351a71gwl2a0p8g-iso9660-image/iso/nixos-minimal-14.02pre5678.gfedcba-i686-linux.iso

[vcunat]

I suppose we need to wait for multiple-output goodies ;-)

[domenkozar]

Let's do that! :)