This fixes an issue in ngMeteor-collections.js that would cause
upserting to fail because of an invalid ObjectID being passed to
collection.update() (as first argument).

This fixes an issue in ngMeteor-collections.js that would cause
removing to fail because of an invalid ObjectID being passed to
collection.remove() (as first argument).

Same fix for upserting.

This reverts commit 1fe9f16.

There seems to be two types of ObjectId:
- A simple string
- Meteor's ObjectId.

This commit allows ngMeteor to handle both types.

Merge urigo/ngMeteor v0.2

…r v0.2"

This reverts commit 27382bb, as it
seems to be causing issues on 0.8.3 and on versions prior to 0.8.2.

… ngMeteor v0.2""

This reverts commit 21e6839.

$$hashKeys will sometimes cause upserting to fail with the below error:
> Error: key $$hashKey must not start with '$'