KJSEmbed support for event handling

KJSEmbed can now handle events. At the moment only mouse events, but the rest will come soon. The example below shows how this can be used in practice. Note that I haven't committed this code yet, so it'll be a couple of days before you can use it.

var scribble = new QWidget();
scribble.line=false;
scribble.x=0;
scribble.y=0;

scribble.mousePressEvent = function(ev)
{
  if ( ev.button == 2 ) {
    this.drawText(ev.x,ev.y,'KJSEmbed!');
  }
  else {
    x = ev.x;
    y = ev.y;
    line=true;
  }
}

scribble.mouseReleaseEvent = function(ev)
{
  if ( line )
    this.drawLine(x,y,ev.x,ev.y);
  line = false;
}

scribble.show();