Points cut of by IDL in 2D

[hpinkos]

From the forum: https://groups.google.com/forum/?hl=en#!topic/cesium-dev/YNQ2QlAC9HY

var viewer = new Cesium.Viewer('cesiumContainer', {     
    sceneMode: Cesium.SceneMode.SCENE2D,
});

viewer.camera.setView({
    destination: Cesium.Cartesian3.fromDegrees(179, 20, 35000000)
});

viewer.entities.add({
    position : Cesium.Cartesian3.fromDegrees(179.9, 40),
    point : {
        pixelSize : 10,
        color : Cesium.Color.YELLOW
    }
});
viewer.entities.add({
    position : Cesium.Cartesian3.fromDegrees(-179.9, 30),
    point : {
        pixelSize : 10,
        color : Cesium.Color.YELLOW
    }
});

[pjcozzi]

Combing with #4179.