Added support for custom display connections in JOGL for JoglNewtWindow

Only JoglNewtWindow supports custom display connections at the moment.
JoglAwtCanvas and JoglNewtAwtCanvas would have to be adapted in a
similar way.

Also, JoglPbufferTextureRenderer and JoglImageLoader call
CapsUtil.getProfile() and would need to be adapted to call
CapsUtil.getProfile(display) to support non-default displays.