[Frontend-GNOME] Fixed allowed proxy port range
[Frontend-GNOME] Minor cosmetic fixes
[Frontend-GNOME] Fixed widget names
[Frontend-GNOME] Implemented GtkBuilder based FilterListWidget
[Frontend-GNOME] Implemented GtkBuilder based ServerListWidget
[Frontend-GNOME] Implemented reading and writing all settings of PreferencesDialog
[Frontend-GNOME] Implemented Server -> Manage in menu bar
[Frontend-GNOME] Use nicer button labels for ServerDialog

Thanks goes to Hylke Bons for mentioning this