[BUGFIX] Bugfixes and optimisations

- Fixed issue causing nested groups not merging namespace correctly.
- Fixed issue causing longer urls (for example: /route) to have higher priority than (/route/match) in some cases.

src/Pecee/SimpleRouter/RouterGroup.php

@@ -93,7 +93,7 @@ class RouterGroup extends RouterEntry {
      * @return self
      */
     public function addSettings(array $settings = null) {
-        if(isset($settings['namespace'])) {
+        if($this->getNamespace() !== null && isset($settings['namespace'])) {
             unset($settings['namespace']);
         }
         if(is_array($settings)) {