Changes

Cleanup GLDrawableFactory API and platform Implementations

- Finish API change using the AbstractGraphicsDevice, which denotes the target device
  for the desired NativeSurface / GLDrawable.
  The AbstractGraphicsDevice argument may be null to reflect the platform's default device.
  Clarified API documentation.
  This move is necessary to make the API coherent.

- createOffscreenDrawable(..) may create a Pbuffer drawable if caps and supported.
  This unifies the functionality with createGLDrawable(..).
  Further more, a Pbuffer drawable is an offscreen as well.

- added createOffscreenSurface(..) following the same behavior as createOffscreenDrawable(..),
  this is a convenient native offscreen surface factory entry.

- removed createGLPbufferDrawable(..), use createOffscreenDrawable(..),
  since it is redundant!

Implementation Details:

- EGLDrawableFactory holds a shared native EGLGraphicsDevice,
  being used by the offscreen EGL drawable (no more multiple creation).

GLPbufferImpl: Remove redundant AWT threading constraints ; Signal dispose to all GLEventListeners at destroy()

DEBUG: GLProfile: Dump GLInfo ; GLContext: SET mappedVersions.. no stack trace

Fix NEWT WindowImpl: setTitleImpl() at native construction.

This tiny fix finally enables the window title setting before setVisible(true)

Fix NEWT GLWindow: Adding missing shared GLContext setter (with unit test)

GLCanvas: Adding convenient constructor for GLCapabilties and Shared Context (with unit test)

Windows WGL fixes updateGraphicsConfiguration(..) and DummyWGLDrawable

WindowsWGLGraphicsConfiguration:
  If updateGraphicsConfigurationARB fails, continue with updateGraphicsConfigurationGDI

WindowsDummyWGLDrawable:
  Utilize proper GraphicsConfiguration selection using updateGraphicsConfiguration()