Merged from trunk:

Merged from trunk:

 * Get rid of the ugly `useFromStdenv' hack in all-packages.nix.
   Instead, use the generic package override mechanism to use packages
   from earlier bootstrap phases.

 * Don't rely on the existence of attributes such as `stdenv.coreutils'.

 * pkgs/tools/networking/nbd: updated to version 2.9.17

 * pkgs/stdenv/generic: added isSunOS attribute, similar to isLinux,
   isDarwin, etc.

 * pkgs/tools/networking/curl: assert that scpSupport is enabled only
   when libssh2 is available

 * pkgs/tools/networking/curl: strip trailing whitespace

 * pkgs/top-level/all-packages.nix: curl cannot support scp on Solaris
   because libssh2 doesn't compile

 * pkgs/top-level/all-packages.nix: don't enable ACL support in rsync
   when building on Solaris

 * pkgs/top-level/all-packages.nix: strip trailing whitespace

svn path=/nixpkgs/branches/parallel-building-merger/; revision=23002