Perform SASLPrep on the username and Resourceprep on the resource

The username is not necessarily a nodepart, therefore SASLPrep is more
appropriate than Nodeprep which we had before.

src/XMPPConnection.m

@@ -52,9 +52,9 @@
 	char *node;
 
 	Stringprep_rc rc;
-	if ((rc = stringprep_profile([username_ cString], &node, "Nodeprep", 0))
+	if ((rc = stringprep_profile([username_ cString], &node, "SASLprep", 0))
 			!= STRINGPREP_OK) {
-		of_log(@"Nodeprep failed: %s", stringprep_strerror(rc));
+		of_log(@"SASLprep failed: %s", stringprep_strerror(rc));
 		assert(0);
 	}
 
@@ -67,6 +67,27 @@
 	[old release];
 }
 
+- (void)setResource: (OFString*)resource_
+{
+	OFString *old = resource;
+	char *res;
+
+	Stringprep_rc rc;
+	if ((rc = stringprep_profile([resource_ cString], &res, "Resourceprep", 0))
+			!= STRINGPREP_OK) {
+		of_log(@"Resourceprep failed: %s", stringprep_strerror(rc));
+		assert(0);
+	}
+
+	@try {
+		resource = [[OFString alloc] initWithCString: res];
+	} @finally {
+		free(res);
+	}
+
+	[old release];
+}
+
 - (void)setServer: (OFString*)server_
 {
 	OFString *old = server;