Update SMW_LanguageDe.php

Add German translation as well as aliases for '_MIME' and '_MEDIA'
Update SMW_LanguageNl.php

Add Dutch translation as well as aliases for '_MIME' and '_MEDIA'. Thanks got to Jan Schoonderbeek (Saruman)
Update SMW_LanguageNl.php

Make translation more consistent to the other special properties.
Update SMW_LanguageNb.php

Add Norwegian translation for '_MIME' and '_MEDIA'. Thanks go to Even Thorbergsen.
Update SMW_LanguageRu.php

Add Russian translation for '_MIME' and '_MEDIA'. Thanks go to Yury Katkov.
Update SMW_LanguageEn.php

Change to capital letters for MIME
Merge pull request #174 from SemanticMediaWiki/I18n2

Adding translations as well as aliases for the new special properties