Bug 972 - Reduce ClassLoader Lookup, i.e. Class.forName(..): GLProfile, GLContextImpl, DisplayImpl

GLProfile, GLContextImpl:
  - ReflectionUtil.DEBUG_STATS_FORNAME: Dump forName stats if set
  - Cache GL*Impl and GL*ProcAddressTable Constructor<?> for GLContextImpl's createInstance(..)
  - Remove off-thread early classloading thread which only adds complications

DisplayImpl:
  - Remove one redundant availability test
Bug 973: NativeWindowFactory: Needs service provider interface (SPI) for TK specific implementations (Scaling)

Add FIXME note ..
Bug 973: NativeWindowFactory: Needs service provider interface (SPI) for TK specific implementations (Scaling)