adds J2S._getKeyModifiers

missing Character.isISOControl

fixes JSTextUI not handling key events

// BH 2/20/2018 12:08:08 AM adds J2S._getKeyModifiers
// BH 2/20/2018 12:59:28 AM adds Character.isISOControl

JSTextUI properly checking KeyListeners

I had some missing (not implemented) code in
sun.awt.image.OffScreenImageSource mainly because I had never
implemented the image producer/consumer business.

I also had a bug in array.clone().


Changes made in:

java.awt.image.BufferedImage
sun.awt.image.OffscreenImageSource
swingjs.JSImageKit

js/j2sApplet.js
js/j2sClazz.js

Classes added:

java.awt.image.ImageFilter
java.awt.image.FilteredImageSource

The issue will be if the developer is using raw raster calls to change
an image. One must call image.checkHavePixels() and possibly even set
image._havePix false first to force the reading of the HTML5 canvas
pixels into the image raster data.

"not implemented" message removed

Applet resizing is possible, but apparently not in Java when the applet
is embedded. So we copy that idea in JavaScript as well. But we still
allow an applet resizer handle. 

TODO: make applet resizer handle able to be removed by developer. Default none?