Previously `ifconfig` would only know link-local addresses
(printed as 'local') and everything else would be 'global'.
This is wrong for site-local and unique local addresses which were
also denoted as global.
So use the already existing helper functions to determine the correct
type of IPv6 address when printing.
Added arduino-nano to BOARD_INSUFFICIENT_MEMORY/BOARD_BLACKLIST following suit
of how arduino-uno is marked, as arduino-nano is mostly an Uno in a different
form factor.