Changes

Fix:
com.jogamp.opengl.test.junit.jogl.acore.TestGLProfile04NEWTOffscreenNoARBCtx
java.lang.AssertionError: Property 'jogl.disable.openglarbcontext' set,
but created w/ ARB 	at org.junit.Assert.fail(Assert.java:88) 	at
org.junit.Assert.assertTrue(Assert.java:41) 	at
org.junit.Assert.assertFalse(Assert.java:64) 	at
com.jogamp.opengl.test.junit.jogl.acore.GLProfile0XBase.validateOnlineOffscreen(GLProfile0XBase.java:920)

Bug 1245: Adding Unit Test, similar to
TestBug816JTabbedPanelVisibilityB849B878AWT
TestBug1245JTabbedPanelCrashAWT passed as expected on GNU/Linux,
Debian8, amd64 w/:
- proprietary NV
- GL_RENDERER   = Gallium 0.4 on AMD ARUBA
 GL_VERSION    = 3.0 Mesa 10.3.2
 GL_VENDOR     = X.Org

Fix: junit/jogl/awt/TestBug1225EventQueueInterruptedAWT and
junit/jogl/util/texture/TestTextureIONEWT replacing import
junit.framework.* with import org.junit.* fixed the "Stub!" Exception
seen when runing the junit tests from inside Eclipse

GLContextImpl: clarify surfacelessOK -> isSurfaceless

Bug 1206 - Security: Clear exposed framebuffer after creation and before
visibility
Experimenting w/ no GLEventListener attached to an GLAutoDrawable, e.g.
GLWindow (onscreen), GLJPanel (fbo offscreen), indeed on some GL
implementations the default framebuffer is uninitialized and hence shows
garbage.
GLDrawableHelper.setViewportAndClear(..)
- Clear framebuffer after setting viewport
- Called from:
  - public final void init(..)
  - public final void reshape(..)
 - Method is used independent of GLEventListener,
  hence this simplifies implementation: removes 'setViewport' criteria
  for init, display, reshape: it is always performed!
Note: We only attempt to help against leaking un-initialized framebuffer
content not against user-app faults, we do not clear a 2nd-buffer
(double-buffering).
Note: We may still be late at resize, i.e. small noisy flickering might
be visible. This might be due to lack of proper vsync.

Bug 1223: Add '-traceMouse' commandline argument to check whether mouse
events are still received after manual maximize