fixes #1646, #3103 - enable cloning for templates, and add read-only options

Since it's nearly the same code, I'd suggest:

```ruby
def lock
  locker('locked')
end

def unlock
  locker('unlocked')
end

private 

def locker(key)
  @config_template.locked = !@config_template.locked
  if @config_template.save
    process_success :success_msg => _("Template #{key}."), :success_redirect => :back
  else
    process_error
  end
end
```