Remove type query parameter from OAuth2 requests.

While the type parameter was required in older versions of the OAuth2
specification, it was removed in version 8. Currently, this breaks OAuth2
against the Dropbox API. Closes #127.

http://tools.ietf.org/html/draft-ietf-oauth-v2-08#section-4.1.1

lib/oauth2.js

@@ -132,21 +132,19 @@ exports.OAuth2.prototype._executeRequest= function( http_library, options, post_
   if(  options.method == 'POST' && post_body ) {
      request.write(post_body);
   }
-  request.end();  
+  request.end();
 }
 
 exports.OAuth2.prototype.getAuthorizeUrl= function( params ) {
   var params= params || {};
   params['client_id'] = this._clientId;
-  params['type'] = 'web_server';
   return this._baseSite + this._authorizeUrl + "?" + querystring.stringify(params);
 }
 
 exports.OAuth2.prototype.getOAuthAccessToken= function(code, params, callback) {
   var params= params || {};
   params['client_id'] = this._clientId;
   params['client_secret'] = this._clientSecret;
-  params['type']= 'web_server';
   var codeParam = (params.grant_type === 'refresh_token') ? 'refresh_token' : 'code';
   params[codeParam]= code;