* Fixed a problem when buttons were deleted on the same frame they were pressed (inside update_property)
* Prevent usage of nul key for a dictionary.
* Provide symetry in the interface for both the array property and dictionary property by first clicking on the field to instantiating the dictionary.
Array (Nil), Array (size 0), Array (size 1)
Dictionary (Nil), Array (size 0), Array (size 1)
* Allow to press enter to confirm a string in line edi.
