luci-app-advanced-reboot: add support for Linksys and Xiaomi devices and misc fixes

Fixes:
* change maintainer's email address
* add rpcd reload to uci-defaults script
* add better messaging with link to README when device isn't detected as
  dual-firmware

Add support for:
* linksys-ea8100v2
* linksys-whw01v1
* xiaomi-ax3600
* xiaomi-ax9000

Signed-off-by: Stan Grishin <stangri@melmac.ca>