Convert cbuildbot over to strict sudo usage.
Convert cbuildbot over to strict sudo usage.

This means that the only sudo interactiveness allowed is from
within SudoKeepAlive; any other usage is an immediate failure.

BUG=chromium-os:18393
TEST=cbuildbot x86-generic-full
TEST=run_test.sh

Change-Id: I9041b90c8fbfbc7c18964316bc77f22bba7fad25
Reviewed-on: https://gerrit.chromium.org/gerrit/15300
Commit-Ready: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>
Reviewed-by: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>
Tested-by: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>

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