Do not require "Delete portal content" for copying.

Requiring "Delete portal content" was introduced accidentally
for copying because of a patch for cutting.

Patch OFS.CopySupport.cb_isCopyable to no longer use the patched
cb_userHasCopyOrMovePermission, which was patched to also require
"Delete portal content" so that cutting works properly.
Merge pull request #5 from 4teamwork/jone-copy

Do not require "Delete portal content" for copying.