adjust keygen to use uuid only for notes (uuid on storage/folders woud need more refactoring)

browser/lib/keygen.js

@@ -1,5 +1,11 @@
+const crypto = require('crypto')
+const _ = require('lodash')
 const uuidv4 = require('uuid/v4')
 
-module.exports = function () {
-  return uuidv4()
+module.exports = function (uuid) {
+  if (typeof uuid === typeof true && uuid) {
+    return uuidv4()
+  }
+  const length = 10
+  return crypto.randomBytes(length).toString('hex')
 }