Fixed handling of native object ids in collection

Also fixed behavior of BSON capable objects.
This helps to use mongoose > 3 with sub schema. It serializes the object and gets rid of 'red herring' parameters in the end.

lib/tcoll.js

@@ -422,14 +422,16 @@ tcoll.prototype._wrapTypes = function(obj) {
 
 tcoll.prototype._ensureIds = function(obj) {
  var self = this;
+ if (_.isFunction(obj.toBSON)) obj = obj.toBSON();
+
  _.each(obj, function (v,k) {
  if (k.length >0) {
  if (k[0]=='$')
  throw new Error("key "+k+" must not start with '$'");
  if (k.indexOf('.')!=-1)
  throw new Error("key "+k+" must not contain '.'");
  }
- if (_.isObject(v)) {
+ if (_.isObject(v) && !self._tdb._gopts.nativeObjectID) {
  if (v instanceof self._tdb.ObjectID) {
  if (v.id<0) {
  v._persist(++self._id)