Added ! to list of escaped characters in sign()

Author: vogonistic

lib/aws.js

@@ -97,6 +97,7 @@ var genericAWSClient = function(obj) {
     var stringToSign = ["POST", obj.host, obj.path, qs.stringify(sorted)].join("\n");
 
     // Amazon signature algorithm seems to require this
+    stringToSign = stringToSign.replace(/!/g,"%21");
     stringToSign = stringToSign.replace(/'/g,"%27");
     stringToSign = stringToSign.replace(/\*/g,"%2A");
     stringToSign = stringToSign.replace(/\(/g,"%28");