Adding localization option for application.
Moving error codes to language files to allow localization.
Example, polish localized version of login controller.
Redesigned internationalization to use gettext library.
Started service translation
Merge branch 'master' into 31-internationalization-translations
Sidebar translations
Merge branch 'master' into 31-internationalization-translations

Conflicts:
	application/views/layouts/sidebar.php
Translation support in views
Added more translations. Enabled localization loading by default, as gettext will simply output original text if no translation found instead of erroring out.
Updated translations
Next set of translations
Added missing translations.
Added error messages translations.
Fixed error message typos.
Fixed default error setting / detection.
Added error messages translations.
Fixed translations
Merge branch 'master' into 31-internationalization-translations
Fixed default language setting
Handling controllers without localized flag well
Handling controllers without localized flag well
Switching default locale
Redesigned language settings to use user-friendly names
Added missing translation for 'week'
Merge branch 'master' into 31-internationalization-translations