Changes

GLFBODrawableImpl: Following suit w/ commit b83b068c0f426f24a58e2bd9f52de9ebd0c7876d, sync GL command stream before FBO reconfig

Even though we currently have no bug experienced on this, it seems to be a good idea for
highly concurrently GL driver implementations.

Bug 634 - Part 1: FBObject, Make MSAA 'samplingSink' mutable and add setSamplingSink(..). Create MSAA samplingSink lazy if null.

FBObject: Rename private fields for better reading: samplesSink* -> samplingSink*

Fix GLAutoDrawable.dispose(): Dispose drawable even w/o context; JAWTWindow.lockSurface(): Check AWT component's native peer

- Fix GLAutoDrawable.dispose(): Dispose drawable even w/o context
  - It is possible to have the GLContext not being created (not made current),
    so drawable shall be disposed independent.

  - Merge Runnable 'postDisposeOnEDTAction' to dispose Runnable for clarity

  - GLDrawableHelper: Split disposeGL from invokeGLImpl for clarity

- JAWTWindow.lockSurface(): Check AWT component's native peer
  - W/o a native peer (!isDisplayable()), JAWT locking cannot succeed.

  - On OSX OpenJDK 1.7, attempting to JAWT lock a peer-less component crashes the VM

  - MacOSXJAWTWindow.lockSurfaceImpl(): Remove redundant null checks

Bug 634 - Part 1: Fix FBObject regression of commit dbc260bd2e917ee9001461749c99da0c9cbfaf9a

- init(..): Query MAX_COLOR_ATTACHMENTS: Remove erroneous samplingSink null check (it's always null)

- reset(..): Create & construct samplingSink if required and missing before detaching all (due to bind)

- setSamplingSink(..) returns previous samplingSink