- StorageWizardDialog is removed, along with bmps it was using;
- EditTextWidget now accepts custom font in constructor;
- ScrollContainer scrollbar now jumps to top when content height changes
so it's "overscrolled";
- IndexPageHandler now does not awaits for `code` GET-parameter, as
local webserver is no longer used to connect Storages;
- CloudManager and all corresponding Storages are updated to support
disconnecting and to notify about successful connection.
While refreshing access_token, some cloud providers also pass a new
refresh_token. Google Drive does not, and accepts the same refresh_token
next time. These changes allow this to happen.