update ifconfig.sh [v9_18]
- make it harder to get the interface numbers wrong by using 'max' to specify the upper bound of the sequence of interfaces and use 'max' when calculating the interface number
- extract the platform specific instruction into 'up' and 'down' and call them from the inner loop so that the interface number is calculated in one place.
- calculate the A and AAAA address in a single place rather than in each command
- use /sbin/ipadm on Solaris 2.11 and greater
(cherry picked from commit abfb5b11)
Closes #3061 (closed)
Edited by Mark Andrews