Differences between LL18 proposed resolutions

Looking at the two proposed resolutions of LL18, here are the differences:

1. Mention of source address selection has been removed from 2.6.1 (the
sentence "For a multi-homed host, the decision as to which source address
to use is also more difficult").  It does seem somewhat relevant to
discuss this in 2.6.1 or 2.6.2.

2. The suggested "MUST ARP for the destination address" has been changed
to "SHOULD ARP".  My understanding was that MUST ARP was selected since
source address/interface selection and the desire to send the packet (as
opposed to dropping it) was presumed. I'd therefore suggest that MUST ARP
be put back.

3. Additional text on "ARP for everything" has been added. This text
appears to conflict with the desired multi-homing behavior, so I would
suggest that we rephrase it to say "In the case of a device with a single
interface and only a link-local address".  Also at the end of the
paragraph, we might add "For suggested behavior in multi-homed hosts, see
Section 3."