Squashed 'platforms/Cross/plugins/' changes from a992d76..04e9bcb

04e9bcb Fix opening a write-only file, beiung careful not to destroy its contents. See http://lists.squeakfoundation.org/pipermail/vm-dev/2014-June/015699.html

git-subtree-dir: platforms/Cross/plugins
git-subtree-split: 04e9bcb9cdd232a941a6c1028df4f3926adb6089
Merge commit '7d9902117d3d22782ad023e9ed1a8466c1e121e7'