title: Error when running the app with mongooseSchema.methods functions
body: <p>Using NodeJS (v0.10.25) and ExpressJS (v4.4.12), and the following Schema</p>
  
  <pre><code>var mongoose     = require('mongoose');
  var Schema       = mongoose.Schema;
  var models       = require('./inherit/models.js');
  
  var userSchema   = new Schema({
      username: { type: String, required: true, unique: true, index: true },
      password: { type: String, required: true , minlength: 128, maxlength: 128 },
      email: { type: String, required: true, unique: true, index: true },
      profileImage: { type: String },
      company: { type: Schema.Types.ObjectId, ref: 'Company' },
      info: {
          name: { type: String, required: true },
          dateOfBirth: { type: Date },
          gender: { type: String, enum: ['M', 'F'] }
      },
      address: [ models.addressModel ],
      contacts: [ models.contactModel ],
      flags: [ models.flagsModel ],
      login: {
          lastDate: { type: Date },
          lastIp: { type: String },
          dtCreate: { type: Date },
          dtUpdate: { type: Date }
      }
  });
  
  userSchema.methods.findComplete = function(findQuery, populateObject) {
      if (typeof populateObject === 'undefined') populateObject = 'company';
  
      return this.model('User').find(findQuery).populate(populate).exec();
  };
  
  userSchema.methods.login = function(username, password) {
      //Some logic
  
      return true;
  }
  
  userSchema.methods.contactTypes = function() {
      return {
          1: 'E-mail adicional',
          2: 'Telefone residencial',
          3: 'Telefone comercial',
          4: 'FAX',
          50: 'Telefone celular',
          51: 'Celular (VIVO)',
          52: 'Celular (TIM)',
          53: 'Celular (Claro)',
          54: 'Celular (Oi)',
          55: 'Celular(Nextel)'
      }
  }
  
  module.exports = mongoose.model('User', userSchema);
  </code></pre>
  
  <p>When trying to run the application i get the following error: </p>
  
  <pre><code>TypeError: Cannot read property 'scope' of undefined
      at model.Object.defineProperty.set [as login] (/home/grupow/Projetos/mean/node_modules/mongoose/lib/document.js:1638:25)
      at applyMethods (/home/grupow/Projetos/mean/node_modules/mongoose/lib/model.js:3151:31)
      at Function.compile (/home/grupow/Projetos/mean/node_modules/mongoose/lib/model.js:3121:3)
      at Mongoose.model (/home/grupow/Projetos/mean/node_modules/mongoose/lib/index.js:392:17)
      at Object.&lt;anonymous&gt; (/home/grupow/Projetos/mean/models/users.js:54:27)
      at Module._compile (module.js:456:26)
      at Object.Module._extensions..js (module.js:474:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:312:12)
      at Module.require (module.js:364:17)
      at require (module.js:380:17)
      at Object.&lt;anonymous&gt; (/home/grupow/Projetos/mean/routes/users.js:5:16)
      at Module._compile (module.js:456:26)
      at Object.Module._extensions..js (module.js:474:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:312:12)
  [nodemon] app crashed - waiting for file changes before starting...
  </code></pre>
  
  <p>When the 'userSchema.methods' are removed, the app run, otherwise, this error will always show up.</p>
  
  <p>Can you please help me?</p>