Fix for watermarks in PHP

Some watermark identifiers were causing signature errors if they
contained special characters such as backslashes.

composer.json

@@ -5,7 +5,7 @@
     "homepage": "https://grabz.it/",	
     "description": "Use our API to allow your app to create images and PDF's from URL's or raw HTML. Additionally GrabzIt allows you to convert online videos into animated GIF's or HTML tables into CSV's.",
 	"license": "MIT",
-	"version":"3.0.2.3",
+	"version":"3.0.3",
 	"autoload": {
 		"classmap": [
 		  "lib/GrabzItAnimationOptions.class.php",

lib/GrabzItClient.class.php

@@ -449,11 +449,11 @@ public function AddWaterMark($identifier, $path, $xpos, $ypos)
 
 		$content .= "--".$boundary."\r\n".
 				"Content-Disposition: form-data; name=\"key\"\r\n\r\n".
-				urlencode($this->applicationKey) . "\r\n";
+				$this->applicationKey . "\r\n";
 
 		$content .= "--".$boundary."\r\n".
 				"Content-Disposition: form-data; name=\"identifier\"\r\n\r\n".
-				urlencode($identifier) . "\r\n";
+				$identifier . "\r\n";
 
 		$content .= "--".$boundary."\r\n".
 				"Content-Disposition: form-data; name=\"xpos\"\r\n\r\n".