Some minor tweaks to get the tests passing again

This needs fixing more completely in the future to use the correct
API, but it gets most of the tests passing for now.

Change-Id: Ide01bccba330e1196c5d060e6f048743f86cbc96

Rendering/ContextOpenGL2/vtkOpenGL2ContextDevice2D.cxx

@@ -83,6 +83,7 @@ void vtkOpenGL2ContextDevice2D::DrawPointSprites(vtkImageData *sprite,
       this->Storage->SpriteTexture->SetRepeat(properties & vtkContextDevice2D::Repeat);
       this->Storage->SpriteTexture->SetInterpolate(properties & vtkContextDevice2D::Linear);
       this->Storage->SpriteTexture->Render(this->Renderer);
+      glEnable(GL_TEXTURE_2D);
       }
 
     // We can actually use point sprites here
@@ -115,6 +116,7 @@ void vtkOpenGL2ContextDevice2D::DrawImage(float p[2], float scale,
   vtkOpenGLClearErrorMacro();
   this->SetTexture(image);
   this->Storage->Texture->Render(this->Renderer);
+  glEnable(GL_TEXTURE_2D);
   int *extent = image->GetExtent();
   float points[] = { p[0]                     , p[1],
                      p[0]+scale*extent[1]+1.0f, p[1],
@@ -148,6 +150,7 @@ void vtkOpenGL2ContextDevice2D::DrawImage(const vtkRectf& pos,
   GLuint index = this->Storage->TextureFromImage(image);
 //  this->SetTexture(image);
 //  this->Storage->Texture->Render(this->Renderer);
+  glEnable(GL_TEXTURE_2D);
   float points[] = { pos.GetX()              , pos.GetY(),
                      pos.GetX() + pos.GetWidth(), pos.GetY(),
                      pos.GetX() + pos.GetWidth(), pos.GetY() + pos.GetHeight(),