Update swordappv2 library

Suppress warnings when SWORD statement entries don't include optional category element:
https://github.com/swordapp/swordappv2-php-library/pull/9
Merge pull request #121 from jwhitney/ojs-stable-2_4

Update swordappv2 library
updated de_DE locale, re: 4a903070a1
corrected error in de_DE locale
*8785* added de_DE locale strings, re: 5977248b94
Merge pull request #123 from mtub/20140706-de_DE-locale

updated de_DE locale according to latest changes to en_US, de_DE locales
*8829* Fix capacity to work with many user agent files
*8824* Cleaning js files errors
*8854* Add config variable to declare X_FORWARDED_FOR header as trusted or untrusted
Merge pull request #137 from ulsdevteam/clarify-x-forwarded-for

*8854* Add config variable to declare X_FORWARDED_FOR header as trusted or untrusted
*6837* Implementing administrator password validation on instalation
Merge pull request #138 from fabioluna/ojs-stable-2_4

*6837* Implementing administrator password validation on instalation
*8880* Use "user.username" as label for username field on password change form