When a MAC address with uppercase letters was provided, parsing would
return an error because the parsing logic would only attempt to remove
normalized versions (all lowercase) from the target list. This would
leave the address with uppercase letters in the target list, which it
would then try to interpet as an Alias. This fixes the bug by using
the original address form when removing it from the target list.
Note: needs refactoring to include an actual alias map example. I was
unable to get this to work for the time being, but this test adds at
least some coverage.
