New Form and List

• The existing Form and List classes have been renamed to ListLegacy and FormLegacy.
• 2 new classes have been created List and Form.
• For the moment both extend the legacy classes and offer a cleaner type safe constructor and showDisplayable and hideDisplayable methods.
• The new classes Form and List can not be used with Display.setCurrent, if used an exception is thrown.
• The methods showDisplayable and hideDisplayable do not affect the the Display.getCurrent state.