Update english.php

Added "Submit" text to language file for buttons.
Update contact.tpl

Changed button from "Continue" to "Submit"
Update contact.php

Changed submit button language call.
Update return_form.tpl

Changed return form button from "Continue" to "Submit"
Update return.php

Changed language call for return form submission button from "Continue" to "Submit"
updated ajax error messages to be display wit new admin design
Merge branch 'master' of https://github.com/opencart/opencart
more api work done
more api work done
fix : unable to post  the data of a product review correctly.
Merge pull request #1645 from Jayin/master

fix : unable to post  the data of a product review correctly.
Added missing install SQL for Events.

Closes: #1643
Merge branch 'master' of https://github.com/opencart/opencart
more api work done
Merge branch 'master' of https://github.com/opencart/opencart
Added remaining event triggers for admin/catalog.

Added return int value when db row created in a model.
Added event triggers for admin/design
Added events for affiliate, coupon, store and backup.

Removed unused model method (addCouponHistory)
Added events to admin/marketing
Merge branch 'master' of https://github.com/opencart/opencart