When using $resource you must setup your actions carefully based on what the server returns.
If the server responds to a request with an array then you must configure the action with
`isArray:true` and vice versa. The built-in `get` action defaults to `isArray:false` and the
`query` action defaults to `isArray:true`, which is must be changed if the server does not do this.
Before the error message was an exception inside angular.copy, which didn't explain what the
real problem was. Rather than changing the way that angular.copy works, this change ensures that
a better error message is provided to the programmer if they do not set up their resource actions
correctly.
Closes#2255, #1044
