Include values for deleted sessions and users in statistics

src/main/resources/views/statistics

@@ -3,7 +3,7 @@
 	"language":"javascript",
 	"views":{
 		"statistics":{
-			"map":"function(doc) {\n  switch (doc.type) {\n  case 'session':\n    if (doc.active == 1) { emit('openSessions', 1); }\n    else { emit('closedSessions', 1); }\n    break;\n  case 'skill_question':\n    if (doc.questionType === 'flashcard') {\n      emit('flashcards', 1);\n    } else {\n      if (doc.questionVariant === 'lecture') { emit('lectureQuestions', 1); }\n      else if (doc.questionVariant === 'preparation') { emit('preparationQuestions', 1); }\n      if (doc.piRound == 2) { emit('conceptQuestions', 1); }\n    }\n    break;\n  case 'skill_question_answer':\n    emit('answers', 1);\n    break;\n  case 'interposed_question':\n    emit ('interposedQuestions', 1);\n    break;\n  }\n}",
+			"map":"function(doc) {\n  switch (doc.type) {\n  case 'session':\n    if (doc.active == 1) { emit('openSessions', 1); }\n    else { emit('closedSessions', 1); }\n    break;\n  case 'skill_question':\n    if (doc.questionType === 'flashcard') {\n      emit('flashcards', 1);\n    } else {\n      if (doc.questionVariant === 'lecture') { emit('lectureQuestions', 1); }\n      else if (doc.questionVariant === 'preparation') { emit('preparationQuestions', 1); }\n      if (doc.piRound == 2) { emit('conceptQuestions', 1); }\n    }\n    break;\n  case 'skill_question_answer':\n    emit('answers', 1);\n    break;\n  case 'interposed_question':\n    emit ('interposedQuestions', 1);\n    break;\n  case 'log':\n    if (['cleanup', 'delete'].indexOf(doc.event) !== -1) {\n      if (doc.payload.type === 'session') {\n        emit('deletedSessions', 1);\n      } else if (doc.payload.type === 'user') {\n        emit('deletedUsers', 1);\n      }\n    }\n    break;\n  }\n}",
 			"reduce":"_count"
 		},
 		"unique_session_creators":{