title: Unable to add parameters that are not defined in mongoose schema
body: <p>Can I add new parameter in mongodb collection, which are not defined in mongoose schema?
  Here is my schema </p>
  
  <pre><code>var mongoose = require('mongoose');
  var Schema = mongoose.Schema;
  
  var UsersSchema = new Schema({
      FirstName : {
          type : String       
      },
      LastName : {
          type : String
      },
      ProfileName : {
          type : String
      },
      EmailID : {     //This may actually take Phone Number depending on user account.
          type : String,
          required : true     
      },
      Login : {
          type : { enum : ['Facebook', 'Gmail', 'Custom'] },
          required : true     
      },
      ContactNumber : 
      {
          type : Number
      },
      Address : {  //Add Geo co-ordinates location later.
          type : {}
      },
      ProfilePic : {
          type : String   //URL to image
      },
      Birthday : {
          type : {}      
      },
      Gender : {
          type : { enum : ['Male', 'Female']}
      },
      CreatedDate : {
          type: Date,
          default: Date.now
      },
      ModifiedDate : {
          type: Date,
          default: Date.now       
      },
      LastLogin : {
          type: Date,
          default: Date.now       
      }
  
  });
  
  module.exports = mongoose.model('Users', UsersSchema);
  </code></pre>
  
  <p>And I want to add some parameters like <strong>EmailVerified</strong> and <strong>MobileNumberVerified</strong>
  Here is my routes code which actually insert data in mongodb</p>
  
  <pre><code>router.post('/api/signup',function(req,res){
      console.log("Registering user");
  
      var user = new Users();
      user.FirstName = req.body.FirstName;
      user.LastName = req.body.LastName;
      user.EmailID = req.body.EmailID;
      user.Login = "Custom";
      user.Password = req.body.Password;
      user.ProfileName = req.body.FirstName + " " +req.body.LastName;
  //    user.Birthday = 
      user.Address = req.body.Address;
      user.Gender = req.body.Gender;
      user.EmailVerified = false; // dynamic parameter
      user.MobileNumberVerified = false; // dynamic parameter
  
  //    user.ContactNumber = req.body.ContactNumber;
      user.save(function(err,user){
          if(err){
              console.log(err);
              res.json(err);
          }else{
              console.log("User Registered");
              res.json({result : 1});
          }
      });
  
  });
  </code></pre>
  
  <p>But in mongodb these fields are not present. I think mongoose doesn't permit dynamically adding parameters.</p>