0025974: Visualization - fix misprints in method naming of Graphic3d_GraduatedTrihedron

V3d_View::GetGraduatedTrihedron() - return configuration structure directly.

OpenGl_View::TriedronDisplay() - do not re-create trihedron on each Display call.
OpenGl_Trihedron::Setup() - eliminate global variables.
OpenGl_PrimitiveArray::buildVBO() - release old VBOs before initialization.

ViewerTest.hxx - move out package header from .cdl file.
ViewerTest::ParseColor() - add new method to parse color arguments in common way.

vzbufftrihedron - improve command syntax.
vgraduatedtrihedron - add options -drawgrid and -drawaxes.

src/OpenGl/OpenGl_PrimitiveArray.hxx

@@ -66,6 +66,9 @@ public:
   //! Notice that this flag does not indicate VBOs validity.
   Standard_Boolean IsInitialized() const { return myIsVboInit; }
 
+  //! Invalidate VBO content without destruction.
+  void Invalidate() const { myIsVboInit = Standard_False; }
+
   //! @return primitive type (GL_LINES, GL_TRIANGLES and others)
   GLint DrawMode() const { return myDrawMode; }