Fix for issue transloadit#8: CURL depricated functions (PHP 5.5)

Fix for deprecated @filename API in curl by using the supported CURLFile class.

lib/transloadit/CurlRequest.php

@@ -45,7 +45,19 @@ public function getCurlOptions() {
         if (is_int($field)) {
           $field = 'file_'.($field+1);
         }
-        $fields[$field] = '@'.$file;
+
+        // -- Start edit --
+        // Edit by Aart Berkhout involving issue #8: CURL depricated functions (PHP 5.5)
+        // https://github.com/transloadit/php-sdk/issues/8
+        if (function_exists('curl_file_create')) {
+          // For >= PHP 5.5 use curl_file_create
+          $fields[$field] = curl_file_create($file);
+        }else{
+          // For < PHP 5.5 use @filename API
+          $fields[$field] = '@'.$file;
+        }
+        // -- End edit --
+
       }
       $options[CURLOPT_POSTFIELDS] = $fields;
     }
@@ -55,6 +67,11 @@ public function getCurlOptions() {
 
   public function execute($response = null) {
     $curl = curl_init();
+
+    // -- Start edit --
+    // For PHP 5.6 Safe Upload is required to upload files using curl in PHP 5.5, add the CURLOPT_SAFE_UPLOAD = true option
+    curl_setopt($curl, CURLOPT_SAFE_UPLOAD, function_exists('curl_file_create') ? true : false);  
+    // -- End edit --
 
     curl_setopt_array($curl, $this->getCurlOptions());