generates a workspace instead of subproject

Initial part of [CB-5921](https://issues.apache.org/jira/browse/CB-5921)
My mistake, apparently it was building with the standard cordova-ios lib, and not my local copy (with your changes). It does seem to generate the workspace now, but there are a couple of warnings that I believe could be cleaned up. I'm trying to isolate those changes now, and will reply shortly.