Abort previous pending XHR when navigating

lib/abort-request.js

@@ -0,0 +1,8 @@
+var noop = require("./util/noop")
+
+module.exports = function(request) {
+  if (request && request.readyState < 4) {
+    request.onreadystatechange = noop
+    request.abort()
+  }
+}