need temporary apply function, or timeout to revert

[Sung Jeho]

it's actually not a bug,

* ufw need temporary apply function, not a enable

  if you setting wrong rule set and enabled it,
  you cannot fix it via remote.

  if did temoporary apply function,
  you can ask someone just reset to revert it.

  "enable" should only doing "enable to boot", not a "apply now"

* timeout to revert

  When you settings some rules or enable entire rules with `--timeout <SEC>` option,
  you should confirm it within <SEC> or revert.

Ok, i'm just setting wrong rules my remote FW, and cannot resolve it until visit next month..
I've setup little "failsafe" code before enable it, but it seems not works..