modules/freifunk: Fix default route display for virtual interfaces. while at it, rework and simplify the code for the status page

git-svn-id: http://svn.luci.subsignal.org/luci/trunk@9666 ab181a69-ba2e-0410-a84d-ff88ab4c47bc
applications/luci_splash: Do not try to get parent interfaces for bridges

git-svn-id: http://svn.luci.subsignal.org/luci/trunk@9667 ab181a69-ba2e-0410-a84d-ff88ab4c47bc