names: add linkinfo kind to type mapping functions
iflist: refactor ifinfomsg processing

Try to determine link->type via link->kind pulled from tb[IFLA_LINKINFO].
Otherwise, use ARPHRD/other means. Finally, only set link->type on an
interface who's initial type was NI_IFTYPE_UNKNOWN.
iflist: remove ethtool stats collection

Rework/Re-enable for SP1. For now we have link stats.
Merge pull request #309 from kmroz/refactor_link_type_determination-2