[libcommhistory] Don't use minimized phone numbers for comparison

We cannot reliably compare minimized phone numbers at this level; the
algorithm can and does fail, and when we're doing it here, there is no
possibility of recovering from that. Use normalized numbers instead, and
rely on contact grouping to combine groups for the same contact or
minimized number in the UI.
[libcommhistory] Combine unresolved groups by short number match

Groups are matched only on full, exact phone numbers, so that phone
number matching can be done more accurately by the contacts layer (which
can correctly handle conflicts). For unresolved phone numbers, we must
combine groups by the short number match so that differently formatted
numbers are still combined for the user despite being separate.
Merge pull request #56 from special/no-minimized-addresses

Avoid using minimized numbers for address matching