* Add warning about matching nodes, only allow one url:port combination of nodes.
* Fix up alert styling.
* Custom network form.
* Add custom network to redux store. Setup infrastructure for removal and display.
* Persist custom networks to LS, show them in display.
* Force chain id, make typing happy.
* Display custom networks in network dropdown.
* Fix form validation, purge unused custom networks.
William O'Beirne