unbound: Fix "register DHCP leases in DNS" config option

The option to register DHCP leases within unbound DNS was configurable via
DNS Resolver GUI, but the setting was ignored. DHCP leases were always applied.

(legacy) move ipsec_idinfo_to_text into vpn_ipsec.conf, move copyright notice with it and cleanup some spacing

Reworked action buttons for list operations

Revert "(legacy) move ipsec_idinfo_to_text into vpn_ipsec.conf, move copyright notice with it and cleanup some spacing"

This reverts commit 96e8bd4c.

(legacy) move ipsec_idinfo_to_text into vpn_ipsec.conf, move copyright notice with it and cleanup some spacing

unbound: introducing overwriting of MX records

(ipsec, legacy) add ipsec (mobile) leases to diag and widget, rename "ipsec list_status" to "ipsec list status", closes https://github.com/opnsense/core/issues/139

(legacy/ipsec) add "Connection method" to phase1 settings, closing https://github.com/opnsense/core/issues/477

(legacy/ipsec) fixes for certref, caref, trust config data instead of reengineering authentication_method again...

DHCP: change column of lease table from "Online" to "Status"

fix for #504

Previously it was not possible to add two host override entries for the same
host-domain combination. Technically this restriction does not exist neither
within unbound nor DNS.

  * Added missing tooltips for existing buttons for list management (add line,
    remove line, move line, clone line)
  * Shortened existing tooltip texts to a minimum
  * Fixed incorrect tooltip texts
  * Changed order of buttons to 1. move item, 2. delete item, 3. add item, 4.
    clone item
  * Changed tooltips "click to toggle enable/disable rule" to "disable rule" and
    "enable rule" corresponding to the current state, respectively.

Changed button icon of "add similar item" from plus to clone symbol.