[WIP] Fixes for "deploy from Windows"

The changes necessary to get brooklyn-sample running on Windows. Must be started with "-Djava.io.tmpdir=C:/temp"


yeah i swithered on this.  don't think there is a clean way to trigger an exception since this is freemarker code, though is there?  if so that would be my preference.  failing that we could set it to `/ERROR-ONBOX_BASE_DIR-not-set/` or something at least to give the user some chance of identifying the problem?