explicitly deleted some gl objects to try addressing memory leaks

app/render/gl/functions.cpp

@@ -114,6 +114,11 @@ void olive::gl::Blit(ShaderPtr pipeline, bool flipped, QMatrix4x4 matrix) {
   func->glDrawArrays(GL_TRIANGLES, 0, 6);
 
   pipeline->release();
+
+  m_vbo2.destroy();
+  m_vbo.destroy();
+  m_vao.release();
+  m_vao.destroy();
 }
 
 void olive::gl::OCIOBlit(ShaderPtr pipeline,

app/render/renderinstance.cpp

@@ -98,6 +98,7 @@ void RenderInstance::Stop()
   buffer_.Destroy();
 
   // Destroy context
+
   delete ctx_;
 
   // Destroy offscreen surface