BUrl: fix handling of @ character

* @ is a separator (between user:password and host) only if there are
no slashes before it
 * All slashes in user and password should be urlencoded (as well as any
@ and :)
 * On the other hand, it's possible to have @ as part of an URL path or
query. An example is Google Maps.

Gets Google Maps working.

src/kits/network/libnetapi/Url.cpp

@@ -659,7 +659,14 @@ BUrl::_ExtractAuthority(const BString& urlString, int16* origin)
 	(*origin) += 2;
 
 
-	int16 userInfoEnd = urlString.FindFirst('@', *origin);
+	int32 userInfoEnd = urlString.FindFirst('@', *origin);
+
+	// if the @ comes after a /, it can't be the delimiter for
+	// user:pasword@host. Characters /:@ in user and password must be escaped.
+	// RFC1738, 3.1, Common Internet Scheme Syntax.
+	int32 nextSlash = urlString.FindFirst('/', *origin);
+	if(userInfoEnd > nextSlash)
+		userInfoEnd = -1;
 
 	// URL contains userinfo field
 	if (userInfoEnd != -1) {