Insert a grid item

We added new InsertChildItem and InsertCategory methods.

You can add them manually in source:

for 9.50/9.51:

CXTPPropertyGridItem* CXTPPropertyGridItem::InsertChildItem(int nIndex, CXTPPropertyGridItem* pItem)
{
 m_pChilds->InsertAt(nIndex, pItem);
 pItem->m_pGrid = pItem->m_pChilds->m_pGrid = m_pGrid;

 ASSERT(pItem->m_pParent == NULL);
 pItem->m_pParent = this;
 pItem->m_nIndent = m_nIndent + 1; 

 pItem->OnAddChildItem();

 if (m_bVisible)
 {
  if (m_bExpanded) m_pGrid->SetPropertySort(m_pGrid->m_properetySort, TRUE);
  else if (m_pGrid->GetSafeHwnd() && m_pChilds->GetCount() == 1) m_pGrid->Invalidate(FALSE);
 }

 return pItem;
}

void CXTPPropertyGridItems::InsertAt(int nIndex, CXTPPropertyGridItem* pItem) {
 m_arrItems.InsertAt(nIndex, pItem);
}