Model Extension Property Definitions With Allowed Values But Without A Default Value Throw Exception In Properties View

If a MED has a property definition that has allowed values (like a boolean property type) but does not have a default value, Eclipse's Properties View cell editor throws an exception when trying to display the initial value (which is null/empty). Since the property definition was setup to have no default value there is not a value that can be returned to represent that since property's with allowed values must return an integer to the Properties View. Returning a -1 throws an IndexOutOfBoundesException and returning 0 (zero) will show the first allowed value but that is not what the property value really is. For 7.6 I recommend just returning the first value so that an exception is not thrown. For 7.7 we need to come up with a better solution.