UPBGE: Fix not culled texts.

Previously the cullings setting (cull enabled and front face) was not
applied before rendering the text objects. It created that if the object
renderd just before this text was not using culling then the text will
not use culling.

To solve this issue a call to Enable(RAS_CULL_FACE) was added in the
funcition RAS_OpenGLRasterizer::DisableForText().

Also functions RenderText3D and RenderText2D set their own front face mode.

source/gameengine/Rasterizer/RAS_OpenGLRasterizer/RAS_OpenGLRasterizer.cpp

@@ -2078,7 +2078,8 @@ void RAS_OpenGLRasterizer::DisableForText()
 {
 	SetAlphaBlend(GPU_BLEND_ALPHA);
 	SetLines(false); /* needed for texture fonts otherwise they render as wireframe */
-	SetFrontFace(true);
+
+	Enable(RAS_CULL_FACE);
 
 	ProcessLighting(false, MT_Transform::Identity());
 
@@ -2149,6 +2150,7 @@ void RAS_OpenGLRasterizer::RenderText3D(
 {
 	/* gl prepping */
 	DisableForText();
+	SetFrontFace(true);
 
 	/* the actual drawing */
 	glColor4fv(color);
@@ -2181,6 +2183,7 @@ void RAS_OpenGLRasterizer::RenderText2D(
 	 * behind quite as neatly as we'd have wanted to. I don't know
 	 * what cause it, though :/ .*/
 	DisableForText();
+	SetFrontFace(true);
 	Disable(RAS_DEPTH_TEST);
 
 	SetMatrixMode(RAS_PROJECTION);