Fix installer isIIS() to include IIS versions greater than 7.
Merge pull request #2672 from tiaitsch85/tiaitsch85-patch-1
API: Implement SS_Map::push() to append values.

FIX: SS_Map::count() not taking into account additional firstItems
Merge pull request #2671 from wilr/ssmapfixes

API: Implement SS_Map::push() to append values.