Fix handling of CIDR in allowed address pairs

A CIDR in allowed address pairs would screw up
the calculation of remote security group member
IP addresses due to a call that assumed each entry
was an IP. This patch fixes that an adds a remote
security group reference to the address pairs SG
test case to exercise this code-path.

Closes-Bug: #1382562
Change-Id: I2676f4b56bce7449579d67fb221b3edb7b885103
Merge "Fix handling of CIDR in allowed address pairs"