[FEATURE] Features and optimisations

- Added where method to RouterRoute to support custom regular expression matches on routes.
- Moved parameters property to RouterRoute class.
- Added IRouteEntry class.

src/Pecee/SimpleRouter/IRouteEntry.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Pecee\SimpleRouter;
+
+interface IRouteEntry {
+
+}