* Added a test for deleting items using JSON:  testDeleteItemFromJson().  As part of that,
  I also:
  * Refactored JsonUtil.getIdFromJsonDoc() to use GSON parsing, which is much more reliable.
  * Added the ability for the RestHelper to handle a body in the delete requests.
  * Changed deleteItemFromJson()'s error return value to be valid JSON:  {error: 'couldn't delete item: " + item}
* Made MongoInventoryDAL.deleteItem more forgiving if a document's parent does not exist.
Merge branch 'master' of https://github.com/dgowpers/glowing-meme