Whitespace standardization in catalog controller
Merge pull request #1416 from opencarthelp/master

Whitespace standardization in catalog controller
Added new sagepay payment modules.
Removed exit statement from start-up when class not found to allow for unit tests to execute properly. This won't change the exit of the app if file not found.
Whitespace standardization in /system
Added tests to master. Unable to merge test-suite branch due to white spaces being removed and conflicts.
Added tests folder.
Added default language fix (Thanks to @DS-Matt) REF: #1405
Merge pull request #1418 from opencarthelp/master

Whitespace standardization in /system
Further changes to white space and also indents.
Merge branch 'master' of https://github.com/opencart/opencart
more api work done
Merge branch 'master' of https://github.com/opencart/opencart
Updated tests/readme.md
Fixed incorrect variable reference in pp express controller.

Closes: #1422
Removed protected property that is no longer used in system/engine/controller.php

Closes #1423
Added missing error language strings during install. Thanks @villagedefrance

Close #1429
Slight change to language string for install.
installer update
Added missing "required" class from install step 3 page.