Disable ripple-lib in Safari iOS < 5 and Safari Mac < 6.

Actively disabling support for these browsers allows us to catch and report the
problem rather than trying to connect and failing for unknown reasons.

web_modules/ws.js

@@ -1,6 +1,40 @@
 // If there is no WebSocket, try MozWebSocket (support for some old browsers)
 try {
-  module.exports = WebSocket
+  module.exports = WebSocket;
 } catch(err) {
-  module.exports = MozWebSocket
+  module.exports = MozWebSocket;
+}
+
+// Some versions of Safari Mac 5 and Safari iOS 4 seem to support websockets,
+// but can't communicate with websocketpp, which is what rippled uses.
+//
+// Note that we check for both the WebSocket protocol version the browser seems
+// to implement as well as the user agent etc. The reason is that we want to err
+// on the side of trying to connect since we don't want to accidentally disable
+// a browser that would normally work fine.
+var match, versionRegexp = /Version\/(\d+)\.(\d+)(?:\.(\d+))?.*Safari\//;
+if (
+  // Is browser
+  "object" === typeof navigator &&
+  "string" === typeof navigator.userAgent &&
+  // Is Safari
+  (match = versionRegexp.exec(navigator.userAgent)) &&
+  // And uses the old websocket protocol
+  2 === window.WebSocket.CLOSED
+) {
+  // Is iOS
+  if (/iP(hone|od|ad)/.test(navigator.platform)) {
+    // Below version 5 is broken
+    if (+match[1] < 5) {
+      module.exports = void(0);
+    }
+  // Is any other Mac OS
+  // If you want to refactor this code, be careful, iOS user agents contain the
+  // string "like Mac OS X".
+  } else if (navigator.appVersion.indexOf("Mac") !== -1) {
+    // Below version 6 is broken
+    if (+match[1] < 6) {
+      module.exports = void(0);
+    }
+  }
 }