Bug 976112

Some node.js application migration may fail if the existing application
has a real directory `$OPENSHIFT_NODEJS_DIR/versions/0.6`.
Since we are copying the files over from the new version of the
cartridge, simply remove the files during migration so that `cp -ad`
does not fail.
Merge pull request #2917 from BanzaiMan/dev/hasari/bz976112

Bug 976112