Update install SQL script

Add extra custom field columns for oc_order table.
Added Meta Tag Keyword on Homepage
Added nl2br opening times on contact page
Fix several typos
Added missing semi-colon. Closes #1565
Updated config_ftp_host to config_ftp_hostname in admin/controller/extension/installer.php

Closes #1559
Reduced icon size on dashboard to fit when viewing on smaller window (before layout switches smaller)

Closes #1553
Added missing Amazon Checkout icon in admin area.

Closes #1545
Updated SQL file to alphabetical for recurring payment tables.

Closes #1566
Changed double to single quotes in language file.

Closes #1442
Merge pull request #1563 from Milow/typo-fixes

Fix several typos
Merge pull request #1449 from hellaslubo/patch-order-custom-columns

Update install SQL script
Added 503 header response with retry time of 60 minutes when in maintenance mode. Prevents indexing of site.
Merge branch 'master' of https://github.com/opencart/opencart
more api work done
Merge branch 'master' of https://github.com/opencart/opencart
https://github.com/opencart/opencart/issues/1564
Merge pull request #1552 from eka7a/master

Added Meta Tag Keyword on Homepage
more api work done
Fixed Alerts Filter Link
Fixed SEO URL Scheme Host