Adding GEOMETRY_SHADER support in ShaderCode, adding core GL3/GEOMETRY_SHADER unit tests. ; Simplified GLContext version number

- Adding GEOMETRY_SHADER support in ShaderCode, adding core GL3/GEOMETRY_SHADER unit tests

  Chuck Ritola reported in December 2012 that we lack support of GEOMETRY_SHADER
  and he provided a test case.

  The latter is cleaned up to use GL3 core profile features only
  tesing a pass-through and the flip-XYZ geometry shader.

  ShaderUtil is fixed.

- Simplified GLContext version number
  The OpenGL major/minor version is now hold in a VersionNumber instance
  to simplify usage. Also expose it via getGLVersionNumber() while marking
  getGLVersionMajor() and getGLVersionMinor() deprecated.
Move all Exclusive Context Thread (ECT) tests to it's own package to de-clutter core test package
Fix Bug 666: GLBase.java line 438 contained some invalid trailing characters (regression from e7064ece049705e013d80985eae698ce0ee3c4e3)