TO-DO
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* Do more error/status checking on the install of tailscale entware packages, and during the startup of the service/connection... and if it errors out, present better messaging around that, and potentially stopping the script in order to do more troubleshooting.
* Add script auto update and TailScale auto update (when a new version presents itself) (@jksmurf)

DONE
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* Wording change per @jksmurf: Configure Router as Exit Node: A Tailscale Exit Node is a feature that lets you route all internet traffic, including internet traffic from non-Tailscale devices, through a specific device on your Tailscale network (known as a tailnet). The device routing your traffic (this router) is called an 'exit node'. Please indicate below if you want to enable this feature
* BUG: issuing R for restart the custom setting get reset to original without -accept-routes (custom settings)
* check uptime of the router, and if it's less than 5 minutes after script starts, send a notification that the router just rebooted
* check entware version for armv7-2.6 cpu/arch, then install the tailscale_nohf package, else just the normal tailscale package.
* Add an option for a "tailscale up --reset" for those needing a reset
* Show tailscale binary version in UI
* Gray out the (O) option on operations menu if Custom isn't enabled
* Provide for a method to update the Tailscale binaries to the latest version
* Build a services-start option to allow for auto-start after router reboot