Added subscribe to object update

Added code to subscribe to updates of the context object.
Also resolved some JSLint warnings.
LoadData should have been implemented as a function and I will correct that. Thank you for that. Its a function that eventually does something with the data. As a answer to your question regarding when it might be possible that you receive a GUID instead of an object. This was the case from a certain Mendix 4 version. (So Legacy purposes). If you want to develop only for Mendix 5 you can shorten this function down allot because you will always get a Mendix Object.