Add some documentation about remember me, and domain

Author: xrobau

app/sprinkles/account/config/default.php

@@ -55,11 +55,37 @@
     * RememberMe Package Settings
     * ----------------------------------------------------------------------
     * See https://github.com/gbirke/rememberme for an explanation of these settings
+    *
+    * Note that the 'domain' field can be set to match your top-level-domain if you
+    * want to send the rememberme to all hosts in your domain.  An automatic config
+    * of this can be done in your config.php with code similar to this:
+    *
+    * if (!empty($_SERVER['SERVER_NAME']) && filter_var($_SERVER['SERVER_NAME'], \FILTER_VALIDATE_IP) === false) {
+    *    $darr = explode(".", $_SERVER['SERVER_NAME']);
+    *    array_shift($darr);
+    *    $conf['session']['cookie_parameters'] = [ "lifetime" => 86400, "domain" => ".".join(".", $darr), "path" => "/" ];
+    *    $conf['remember_me'] = [ "domain" => ".".join(".", $darr) ];
+    * }
+    *
+    * (Or, for production, you can hard-code the domain rather than calculating it on each page load)
+    *
+    * This is DELIBERATELY NOT TURNED ON BY DEFAULT!
+    *
+    * If you enable the 'domain' (on both the session and the remember_me cookies)
+    * you will be sending your authentication cookies to every machine in the
+    * domain you are using. This may not be bad if you control the domain, but
+    * if you are using a VPS and the hostname of the machine you are connecting to
+    * is, for example, host2.vps.blah.com, and you connect to host20.vps.blah.com,
+    * your browser will send your (super secret) cookies to host20.vps.blah.com.
+    *
+    * You only want to turn this on if you want machine1.foo.com to receive the
+    * cookies that THIS MACHINE (machine2.foo.com) set. 
     */
     'remember_me' => [
         'cookie' => [
             'name' => 'rememberme',
         ],
+        'domain' => null,
         'expire_time' => 604800,
         'session'     => [
             'path' => '/',

app/sprinkles/account/src/Authenticate/Authenticator.php

@@ -118,12 +118,12 @@ public function __construct(ClassMapper $classMapper, Session $session, Config $
         $this->rememberMe->getCookie()->setPath($this->config['remember_me.session.path']);
 
         // Set expire time, if specified
-        if ($this->config->has('remember_me.expire_time') && ($this->config->has('remember_me.expire_time') != null)) {
+        if ($this->config->has('remember_me.expire_time') && $this->config->has('remember_me.expire_time') != null) {
             $this->rememberMe->getCookie()->setExpireTime($this->config['remember_me.expire_time']);
         }
 
         // Set domain, if specified
-        if ($this->config->has('remember_me.domain') && ($this->config->has('remember_me.domain') != null)) {
+        if ($this->config->has('remember_me.domain') && $this->config->has('remember_me.domain') != null) {
             $this->rememberMe->getCookie()->setDomain($this->config['remember_me.domain']);
         }