Minor bug fixes,

On demo app:

• The Person.Id on the structure had the incorrect Name in JSON of _Id. it should be _id
  • This would lead to _Id to be a valid attribute of the document and 2 id's would show up.

On MogoDB Core:

• Mongo CreateOrUpdate method, was incorrectly passing the _id attribute as "" for new documents. This would lead to the creation of a document with an empty but valid _id.

• Updated example to include a date attribute in collection

Removed ardoJSON dependency