Updated CHANGES.txt with the updates from 4.8.0-beta00002
Updated CHANGES.txt with the updates from 4.8.0-beta00002

NightOwl888/lucenenet,apache/lucenenet,NightOwl888/lucenenet,NightOwl888/lucenenet,sisve/lucenenet,laimis/lucenenet,apache/lucenenet,apache/lucenenet,sisve/lucenenet,apache/lucenenet,jeme/lucenenet,jeme/lucenenet,NightOwl888/lucenenet,jeme/lucenenet,laimis/lucenenet,jeme/lucenenet