Updated chat UI

...quasseldroid_ng/ui/chat/chatview/ChatMessageRenderer.java

...uschku/quasseldroid_ng/ui/chat/fragment/ChatFragment.java

...in/java/de/kuschku/quasseldroid_ng/ui/theme/AppTheme.java

...n/java/de/kuschku/quasseldroid_ng/ui/theme/ThemeUtil.java

app/src/main/res/layout/fragment_chat.xml

app/src/main/res/values/attrs.xml

app/src/main/res/values/strings_format.xml

app/src/main/res/values/themes.xml