Bug 665 (part 3) - Allow dis-association of GLContext's GLDrawable .. - Add EGL/ES2 tests, attempt to fix wrapped EGL case

- Bug 665 (part 2) was commit 7fd5f76e1eb4bbf93fe9b1171744bd755d8f96e4

- Add EGL/ES2 tests in
  - TestGLContextDrawableSwitch01NEWT
  - TestGLContextDrawableSwitch11NEWT

- Attempt to fix wrapped EGL case (incomplete)
  - Using EGL/ES w/ non native EGL device/surface, but natively wrapped instances (most of the cases),
    a 'complicated' delegation of
       Native-Upstream -> EGL-Proxy -> EGL-Instance
    is being used heavily relying on the objects lifecycle.
    GLEventListenerState tries to roll back the realized state
    and even sets the upstream device handle,
    but this doesn't seem to be sufficient on X11.

Discussion:

It might turn out that we only can implement the survival of GLContext
and it's display device reliable w/ EGL within the GLAutoDrawable implementation,
which can hold the previous not destructed instances.