Update order.php
Update product.php
Update header.php
Update download.php
Added missing semi-colons to echo Closes #1565
Merge pull request #1550 from gob33/v1.5.6.x

V1.5.6.x "Incorrect file type" when uploading
Updated changelog for issue #1550
Merge branch 'v1.5.6.x' of https://github.com/opencart/opencart into v1.5.6.x