JS: add standard keyboard shortcuts for New, Open, Save, Save As, and Exit
JS: add standard keyboard shortcuts for New, Open, Save, Save As, and Exit

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

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