Importing Price Module from Excel Prestashop 1.6

Develop a new price list import module from Excel for a site based on PrestaShop 1.6.
To import from Excel, a PHPExcel library is used.
To eliminate memory failure, a block reading mechanism from the xls file has been implemented with a subsequent block record in the BD table.
To eliminate the problems with the expiry of the PHP script implemented the mechanism of multiple consecutive ajax-start of the PHP script from JavaScript until the full reading of the original xls file.