add fix for LanguageFallbackCollector, bump junit version to 4.11

In some cases the new lucene LanguageFallbackSortingTopDocsCollector ignored the fallbackpriority parameter. This has been fixed, the request parameter "languagefallbackpriority" will now be used regardless if the request was created via the Java API or the REST API.

Adds a new Test-File for CRRequest class and bump jUnit version to 4.11 (including minor fixes in test classes)