mongodb/mongo-csharp-driver — pull request #190 by ExM (2014-10-06 14:01:33+00:00)
Title: CSHARP-1080: fix unexpected change non id field name in BSON document

https://jira.mongodb.org/browse/CSHARP-1080

I want to serialize following class:
```csharp
public class TestModel_CustomNotId
{
[BsonElement("id")]
public ObjectId Id { get; set; }
}
```
I expected Id field to be serialized as "id",
but the result BSON document is containing "_id" field.