GUI-1231: VPC support for scaling group wizard and detail page

https://eucalyptus.atlassian.net/browse/GUI-1231
https://eucalyptus.atlassian.net/browse/GUI-1232
the '>' here isn't valid XHTML, it should be escaped via an HTML entity (&gt;).  Or better yet, we could simplify the ng-show attribute to just `ng-show="vpcSubnetNames.length"`