When instances are ratelimited (when a captcha is returned instead of
the user's search results) the user can now hop to a new instance via
Farside, a new backend service that redirects users to working instances
of a particular frontend. In this case, it presents a user with a
Farside link to a new Whoogle (or Searx) instance instead, so that the
user can resume their search.
For the generated Farside->Whoogle link, the generated link includes the
user's current Whoogle configuration settings as URL params, to ensure a
more seamless transition between instances. This doesn't translate to
the Farside->Searx link, but potentially could with some changes.
This checks the latest released version of Whoogle against
the current app version, and shows an "update available"
message if the current version num < latest release num.
Closes#305
