fix(*): make sure all functions are named consistently

In node 4.x for the bson-ext module we are not getting a valid
function name for these types, and therefore the build breaks.
This change ensures all functions have an accessible type name,
which will additionally be useful during debugging in some cases.

lib/bson/code.js

@@ -8,12 +8,12 @@
  * @param {Object} [scope] an optional scope for the function.
  * @return {Code}
  */
-var Code = function Code(code, scope) {
+function Code(code, scope) {
   if (!(this instanceof Code)) return new Code(code, scope);
   this._bsontype = 'Code';
   this.code = code;
   this.scope = scope;
-};
+}
 
 /**
  * @ignore

lib/bson/decimal128.js

@@ -152,10 +152,10 @@ var invalidErr = function(string, message) {
  * @param {Buffer} bytes a buffer containing the raw Decimal128 bytes.
  * @return {Double}
  */
-var Decimal128 = function(bytes) {
+function Decimal128(bytes) {
   this._bsontype = 'Decimal128';
   this.bytes = bytes;
-};
+}
 
 /**
  * Create a Decimal128 instance from a string representation

lib/bson/int_32.js

@@ -6,12 +6,12 @@
  * @param {number} value the number we want to represent as an int32.
  * @return {Int32}
  */
-var Int32 = function(value) {
+function Int32(value) {
   if (!(this instanceof Int32)) return new Int32(value);
 
   this._bsontype = 'Int32';
   this.value = value;
-};
+}
 
 /**
  * Access the number value.

lib/bson/map.js

@@ -6,7 +6,7 @@ if (typeof global.Map !== 'undefined') {
   module.exports.Map = global.Map;
 } else {
   // We will return a polyfill
-  var Map = function(array) {
+  var Map = function Map(array) {
     this._keys = [];
     this._values = {};
 

lib/bson/objectid.js

@@ -28,7 +28,7 @@ try {
  * @property {number} generationTime The generation time of this ObjectId instance
  * @return {ObjectID} instance of ObjectID.
  */
-var ObjectID = function ObjectID(id) {
+function ObjectID(id) {
   // Duck-typing to support ObjectId from different npm packages
   if (id instanceof ObjectID) return id;
   if (!(this instanceof ObjectID)) return new ObjectID(id);
@@ -70,7 +70,7 @@ var ObjectID = function ObjectID(id) {
   }
 
   if (ObjectID.cacheHexString) this.__id = this.toString('hex');
-};
+}
 
 // Allow usage of ObjectId as well as ObjectID
 // var ObjectId = ObjectID;

lib/bson/timestamp.js

@@ -8,15 +8,15 @@ var Long = require('./long');
  * @param {number} high the high (signed) 32 bits of the Timestamp.
  * @return {Timestamp}
  */
-var Timestamp = function(low, high) {
+function Timestamp(low, high) {
   if (low instanceof Long) {
     Long.call(this, low.low_, low.high_);
   } else {
     Long.call(this, low, high);
   }
 
   this._bsontype = 'Timestamp';
-};
+}
 
 Timestamp.prototype = Object.create(Long.prototype);
 Timestamp.prototype.constructor = Timestamp;