Allow programatic save

[dataarts]

Allow programatic save

[stellatigre]

This issue still occurs in the latest build - this functionality can be invoked by firing the fake click event on the save button:

function saveDatGUI() {
    dat.dom.dom.fakeEvent($('.cr .button')[0], 'click');
}

but that feels hacky. This functionality would be useful in writing tests which involve a datgui component.
If it's deemed not an issue, perhaps close this ?