Combine connection panel with server panel (close #102)

po/POTFILES

@@ -1,5 +1,4 @@
 data/ui/album-headerbar.ui
-data/ui/connection-panel.ui
 data/ui/cover-panel.ui
 data/ui/library-panel.ui
 data/ui/playlist-panel.ui
@@ -9,7 +8,6 @@ data/ui/window.ui
 src/albumheaderbar.py
 src/application.py
 src/client.py
-src/connectionpanel.py
 src/coverpanel.py
 src/librarypanel.py
 src/main.py