This method is used to rebuild the package against iplist mapping when
needed. When a node gained service event occurs, threshd has to determine
which package the ip/service combination is in, but if the interface is a
newly added one, the package iplist should be rebuilt so that threshd
could know which package this ip/service pair is in.
This method is used to determine if the named interface is included in
the passed package definition. If the interface belongs to the package
then a value of true is returned. If the interface does not belong to the
package a false value is returned.
Note: Evaluation of the interface against a package
filter will only work if the IP is already in the database.