luci-app-cjdns: luci admin support for cjdns-v20.2 (#394)

luci-app-cjdns: luci admin support for cjdns-v20.2 (#394)

* luci-app-cjdns: luci admin support for cjdns-v20.2

* adds layer 2 and 3 address display column
* fixes switch label pinger
* get version from addr string
* parse addr string for peerStats publicKey

Signed-off-by: William Fleurant <william@netblazr.com>
* luci-app-cjdns: bump release, update repo-url and license year

Signed-off-by: William Fleurant <william@netblazr.com>
* luci-app-cjdns: support views for 17.01 and 18.06
- fixed user/name column
- removed latency column
- combind peerstats functions
- fix css on overview page
- table displays with `cbi_update_table` with fallback
- columns ordered similar to peerStats.js output
- normalized XHR polling to mimic wireless.htm by jow@openwrt

Signed-off-by: William Fleurant <william@netblazr.com>