Revert "(bug 260) Wrap <pre> overflow properly."

Revert "(bug 260) Wrap <pre> overflow properly."

Due to bug 38800. Just reverting to prevent accidental deployment in
1.20wmf9. I would set a fixme status instead if there was such a thing.

The problem with this is that it breaks formatting of thousands of
Wikipedia articles due to interaction with SyntaxHighlight_GeSHi. I'm
sure some satisfactory solution can be found which fixes both bugs, but
leaving this commit deployed is not a good interim solution.

This reverts commit 782b9f177404f02417c03abaf96b371e1462f160.

Change-Id: I1977f093563b5658def9ba57a6ea6cfa9796f795