Code cleanup and misc fixes

* Properly implement exceptions.
* Allow passing custom eventloop and poll interval to constructor.
* Fix some typos, cleanup code.

src/WatchErrorException.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace NoccyLabs\React\Inotify;
+
+class WatchErrorException extends InotifyException
+{
+    
+}