oauth2: Strict Matching Default True

This changes the default for Strict Matching from `false` to `true` so
that new emails are strict unless explicitly set otherwise. This also
adds some descriptive comments to the getter and setter.

include/class.email.php

@@ -1394,10 +1394,16 @@ static function create($ht=false) {
  *
  */
 class EmailAccountConfig extends Config {
+    /*
+     * Get strict matching (default: true)
+     */
     public function getStrictMatching() {
-        return $this->get('strict_matching', false);
+        return $this->get('strict_matching', true);
     }
 
+    /*
+     * Set strict matching
+     */
     public function setStrictMatching($mode) {
         return $this->set('strict_matching', !!$mode);
     }