Fixed several minor UI issues.

...java/de/kuschku/quasseldroid_ng/ui/chat/MainActivity.java

...asseldroid_ng/ui/chat/drawer/BufferViewConfigAdapter.java

...e/kuschku/quasseldroid_ng/ui/chat/drawer/NetworkItem.java

...oresettings/network/server/NetworkServerEditActivity.java

.../kuschku/util/observables/lists/ObservableSortedList.java

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

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

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

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