title: How to create mongodb collection without _id
body: <p>My project was build on GMONGO framework and all the domains were created with attribute id as a string.So grail frame work will create mongodb collections with _id attribute when application is app.
         In UI there was a limitation to retrive _id.So in service "_id" is rewrite to "id" to overcome the issue.
       Could we created collections with "id" by default rather than "_id"?</p>