Avoid the creation of properties by mistake

[pgambier]

The same syntax is used to create a new property and to assign a value to an existing one which can lead to mistakes.

Example :

transformer('PST_ID').phaseTapChanger.tapPosition = 20

The value of the tap position for Boutre is assigned to 20.

transformer('PST_ID').phaseTapChanger.tapPoistion = 20

The tapPoistion property is created and assigned to 20.

Suggestions :

1. Change the syntax
2. Create a safe mode to avoid the creation of properties if not necessary