Fix issue where parallel_emerge installs wrong packages when portage is updated.
Fix issue where parallel_emerge installs wrong packages when portage is updated.

Currently, if Portage is upgraded, parallel_emerge rebuilds a ton of packages
from source, but also doesn't build the right packages. The reason for this bug
is that parallel_emerge passes the wrong arguments to itself when it restarts.
In this case it both loses the -uDNv arguments and the -g argument, so it both
installs unnecessary packages but also fails to upgrade other packages.

BUG=chromium-os:15032
TEST=Test installing hard-host-depends with parallel_emerge and verify right
     packages are updated.

Change-Id: I1155f67a003e531bc2df3695178d1f94c8a17f71
Reviewed-on: http://gerrit.chromium.org/gerrit/470
Reviewed-by: Nick Sanders <f4566bb3c90c0bf5fa0906b296b1da45051a62ee@chromium.org>
Tested-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>

chadversary/chromiumos.chromite,chadversary/chromiumos.chromite,zhang0137/chromite,coreos/chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite