Don't validate shader programs on MacOS X

If the paint event is called before the view is visible, validation
of the shader program will cause an error on MacOS X 10.8 and forward,
stating that the operation was ignored.

Fwk/VizFwk/LibRender/cvfOpenGL.cpp

@@ -200,7 +200,11 @@ void OpenGL::cvf_check_ogl(OpenGLContext* oglContext, const CodeLocation& codeLo
             CVF_ASSERT(oglContext->isCurrent());
 
             Logger* logger = oglContext->group()->logger();
+#if defined(CVF_OSX)
+            if (logger && (err != GL_INVALID_FRAMEBUFFER_OPERATION))
+#else
             if (logger)
+#endif /* defined(CVF_OSX) */
             {
                 String errCodeStr = mapOpenGLErrorToString(err);
                 String msg = "OGL(" + errCodeStr + "): ";

Fwk/VizFwk/LibRender/cvfShaderProgram.cpp

@@ -286,7 +286,9 @@ bool ShaderProgram::useProgram(OpenGLContext* oglContext) const
     }
 
     CVF_ASSERT(OglRc::safeOglId(m_oglRcProgram.p()) != 0);
+#ifndef CVF_OSX
     CVF_ASSERT(validateProgram(oglContext));
+#endif
     
     // Need this check to clear any "hanging" errors that is not produced by glUseProgram below, but still 
     // will make this method return false.