Parse IPv6 addresses for Backfire
URL leading double-slash fix

Leading double slash breaks some ancient luci versions and doesn't
return the intended contents
Fix parsing of bridge list

Sometimes only the interface column is filled in (which means this is
*not* a bridge), ignore those lines. Fixes a Parse_Error for some
configurations.
Fix version parsing for some luci versions
Extract Luci version from verbose version info
cosmetic change