pfSense

Don't enable interfaces_use by default. Add checkbox to enable on Advanced
tab, in case there are scenarios where it's desirable. Ticket #4341

Code style etc inc vwx3

rebased version with conflicts resolved due to a bunch of recent changes
in vpn.inc

Merge pull request #1541 from phil-davis/Code-Style-etc-inc-z

Check if it's an array before call foreach(). Ticket

Stop trying to fix dns_split during strongswan config generation, we have an upgrade code in place for that, it should fix #4418

dns_split was a comma separated list and moved to use space as separator, provide upgrade code to make sure old configs are converted. Since there was a config upgrade version 11.7 only on master, I pushed it to 11.8 and used dns_split one as 11.7 to be able to backport it to RELENG_2_2. Ticket #4418

Use get_failover_interface here to find appropriate interface. Ticket #4482

same change as previous commit, for IPv6. Ticket #4482

Use the parent interface, not the _vip for interfaces_use. Part of Ticket #4482

Destroy stf interface when 6rd or 6to4 tunnel is disabled. Fixes #4471