[dm-devel] User friendly names patch.

[Benjamin Marzinski]

This is a patch to add the option of more user friendly names for the
multipath maps, in the form of mpath<n>.  It adds a configuration option
"user_friendly_names". If set, it will cause multipath to check a bindings
file for the names. The bindings file (/var/lib/multipath/bindings) has
alias to wwid mappings. If multipath finds its wwid in the file, it uses
the associated alias. If not, it creates a new alias, and adds the binding
to the bindings file. If the config option is not set, multipath defaults
to it's regular behavior. Specific aliases in /etc/multipath.conf override
this behavior.

-Ben