Fix to the way translations are handled. Also updated the german translation with the new strings.

translations/CMakeLists.txt

@@ -0,0 +1,20 @@
+set_directory_properties(PROPERTIES CLEAN_NO_CUSTOM 1)
+
+### translation stuff
+
+file(GLOB TRANSLATION_FILES ${CMAKE_CURRENT_LIST_DIR}/*.ts)
+set(FILES_TO_TRANSLATE_ABSOLUTE)
+foreach(file ${FILES_TO_TRANSLATE})
+    list(APPEND FILES_TO_TRANSLATE_ABSOLUTE "${CMAKE_SOURCE_DIR}/${file}")
+endforeach()
+
+qt5_create_translation(TRANSLATION_MESSAGES ${FILES_TO_TRANSLATE_ABSOLUTE} ${TRANSLATION_FILES})
+qt5_add_translation(TRANSLATION_QM ${TRANSLATION_FILES})
+add_custom_target(translations_update DEPENDS ${TRANSLATION_MESSAGES})
+add_custom_target(translations DEPENDS ${TRANSLATION_QM})
+
+IF(APPLE AND UNIX) ## OSX
+      install(FILES ${TRANSLATION_QM} DESTINATION MultiMC.app/Contents/MacOS/translations)
+ELSE()
+      install(FILES ${TRANSLATION_QM} DESTINATION translations)
+ENDIF()