NEWT X11 DisplayDriver.dispatchMessagesNative(): Avoid aDevice NPE while being pulled
EGLDisplayUtil.eglCreateEGLGraphicsDevice(..): Don't open() device implicit; EGLDrawableFactory.mapAvailableEGLESConfig(..): Clarify
Bug 950 - Recognize full FBO capabilities for ES 3.0 - [GLContext|GL].hasFullFBOSupport() == true

OpenGL ES 3.0 supports full framebuffer operations, incl. multiple color-attachments and multisample.

Hence [GLContext|GL].hasFullFBOSupport()  shall returns true w/ a ES 3.0 context.
Bug 948 - NVIDIA 331.38 (Linux X11) EGL impl. only supports _one_ EGL Display via eglGetDisplay(..)

NVIDIA 331.38 (Linux X11) EGL impl. only supports _one_ EGL Display via eglGetDisplay.

  - Subsequent eglGetDisplay(..) calls fail.

  - Using the same 'global' egl-display does work though

Remedy: Add 'GLRendererQuirks.SingletonEGLDisplayOnly'

Detection of quirk is done as usual in GLContextImpl.setRendererQuirks(..),
and EGLDrawableFactory passes the quirk, if detected, down to EGLDisplayUtil.
The latter implements the singleton eglDisplay handle.

EGLDisplayUtil: Cleaned up ..
  - EGLDisplayRef employs the reference handling incl. eglInitialize(..) and eglTerminate(),
    as well as the new singleton quirk.

  - Mark all internal methods 'private',
    to remove possible [untested] sideffects.