Merged Diego's changes for OAuth2.0 server-side flow

src/main/java/org/scribe/builder/api/DefaultApi20.java

@@ -1,5 +1,6 @@
 package org.scribe.builder.api;
 
+import org.scribe.extractors.*;
 import org.scribe.model.*;
 import org.scribe.oauth.*;
 
@@ -22,6 +23,33 @@ import org.scribe.oauth.*;
 public abstract class DefaultApi20 implements Api
 {
 
+  /**
+   * Returns the access token extractor.
+   * 
+   * @return access token extractor
+   */
+  public AccessTokenExtractor getAccessTokenExtractor()
+  {
+    return new TokenExtractor20Impl();
+  }
+	
+  /**
+   * Returns the verb for the access token endpoint (defaults to GET)
+   * 
+   * @return access token endpoint verb
+   */
+  public Verb getAccessTokenVerb()
+  {
+    return Verb.GET;
+  }
+	
+  /**
+   * Returns the URL that receives the access token requests.
+   * 
+   * @return access token URL
+   */
+  public abstract String getAccessTokenEndpoint();
+	
   /**
    * Returns the URL where you should redirect your users to authenticate
    * your application.

src/main/java/org/scribe/builder/api/FacebookApi.java

@@ -5,8 +5,14 @@ import org.scribe.utils.*;
 
 public class FacebookApi extends DefaultApi20
 {
-  private static final String AUTHORIZE_URL = "https://graph.facebook.com/oauth/authorize?response_type=token&client_id=%s&redirect_uri=%s";
+  private static final String AUTHORIZE_URL = "https://www.facebook.com/dialog/oauth?client_id=%s&redirect_uri=%s";
 
+  @Override
+  public String getAccessTokenEndpoint()
+  {
+    return "https://graph.facebook.com/oauth/access_token";
+  }
+  
   @Override
   public String getAuthorizationUrl(OAuthConfig config)
   {