IPsec tunnels: enhance table of configured tunnels

(legacy) bring down interface on change in interfaces_assign.php, related to https://github.com/opnsense/core/issues/654

In languages where scoping matters this would be really iffy...

certs: refactor ca_chain for #664

Time to flip defaults for 16.1.  :)

some translation fixes

o Help link is in the menu and was already removed from MVC version
o Display user@host.domain in MVC too
o Logout is in the menu too

We might be able to salvage all the space now that the menu is consisten
and transform the top bar into the tile bar instead...

Log links still show, but will be killed as well early in the 16.1
series.

o is_install_media() was being misused.  In the instance of dhcp6,
  the backup file did not even exist, I think someone did copy+paste
  the IPv4 code back in the day and the actual backup was never added.

o match_wireless_interface() was moved to interfaces.inc where it
  belongs.

OpenVPN Client Export: add CA chain to CA certificates

While there, move some stray menu items to their respective module
menu and minimise the padding of the menu to reclaim the space added
by the fixed-width icon behaviour.

Looking good!  :)

Suggested by: @8191

CA Generation: fix internal intermediate CA creation

Internal intermediate CAs were not correctly refered back to the signing CA.

Change columns of IPsec tunnels as follows:

  * P1 Protocol, P1 Transforms --> Phase 1 Proposal to show Enc. Alg. + Auth
    Alg. + DH Group

  * Add column Authentication for P1 to show "RSA" or "PSK" (or Xauth for IPsec
    mobile)

  * Move P2 Protocol, Mode --> Type to show IP version + enc. + mode

  * P2 Transforms --> Encryption Algorithms

  * P2 Auth Methods --> Authenticity Algorithms

  * Add column PFS for P2

Menu: fixed menu for IPsec Mobile Clients after apply