code optimization
Added pre events.
Fixes a typo on the product return page.
Merge pull request #1693 from stan-bg/patch-15

code optimization
Merge branch 'master' of git@github.com:opencart/opencart.git
Merge pull request #1694 from steven-wm/master

Fixes a typo on the product return page.
Merge branch 'master' of git@github.com:opencart/opencart.git