JS: set the JaamSimModel for a new entity
JS: set the JaamSimModel for a new entity

This is a fudge that avoids the need to create new constructors for EVERY
sub-class of Entity that include an argument for JaamSimModel.

Signed-off-by: Harry King <409587b9e6671aa0763646191d292852dc49a658@gmail.com>

jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim,jaamsim/jaamsim