VTiger 7 compatibility

[abunet]

• VT7 Compatibility (getColumnFields)
• Added product details for SalesOrder, PurchaseOrder, Quote, Invoice

https://github.com/sardoj/VTRestfulAPI/blob/master/src/modules/RestfulApi/actions/Api.php#L459

$m_result = $focus->column_fields;

changed in:

$m_result = $focus->column_fields->getColumnFields();

if($this->module == 'Invoice' || $this->module == 'Quotes' || $this->module == 'SalesOrder' || $this->module == 'PurchaseOrder') { 
                $recordModel = Vtiger_Record_Model::getInstanceById($id);
                $m_result["products"] = $recordModel->getProducts();
            }

[sardoj]

Hello, thank you for your contribution. Please can you check if the compatibility with Vtiger 6 is ok and make a Pull Request?