Issues with the "address" field type

[tabacitu]

@OwenMelbz ,

I've found some issues here, wondering if you could take a look sometime, you know this part best.

1. I can't go to EDIT an entry, empty the address field and the save that empty value to the database. It does not get saved, probably because that doesn't clear the hidden input.

2. I get a javascript error on the CREATE screen, about parsing the JSON. I used attribute casting to array (not that it matters, I think - it's the create screen, there is no value).
   
   

Cheers!

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Also, figured out a way for us to better test that nothing breaks when we make changes: we create an entity with ALL the field types and we include it in the Demo. So when we want to test a field, we just Add and Edit a new "Foo".

[OwenMelbz]

@tabacitu well spotted :) Should now be able to clear old saved entries, and it wont try parse empty values with #188