Revert "Be compatible with the stdlib for now ('static shell)"

This reverts commit a601d049feff5768b0d99b9fcec807b277fa4c81.
Add back fix for cross compile tests

This change was accidentally included in the reverted commit.
auto merge of #513 : bkoropoff/cargo/revert-static, r=alexcrichton

This reverts a commit that worked around an overly restrictive lifetime bound on the `Writer` impl for `Box<Writer>` in libstd.  Now that this restriction has been lifted, the workaround can be reverted.