1211 Add descriptions to public interfaces.

Author: Richard Blaylock

api/src/main/java/com/stormpath/sdk/oauth/OAuthStormpathFactorChallengeGrantRequestAuthenticator.java

@@ -17,6 +17,10 @@
 
 
 /**
+ * Interface denoting a Stormpath Factor Challenge Grant-specific {@link OAuthRequestAuthenticator}.
+ * It is used to authenticate an account using a challenge to a factor and receive in exchange
+ * a valid OAuth 2.0 token.
+ *
  * @since 1.3.1
  */
 public interface OAuthStormpathFactorChallengeGrantRequestAuthenticator extends OAuthRequestAuthenticator<OAuthGrantRequestAuthenticationResult> {

api/src/main/java/com/stormpath/sdk/oauth/OAuthStormpathFactorChallengeGrantRequestAuthenticatorFactory.java

@@ -16,6 +16,8 @@
 package com.stormpath.sdk.oauth;
 
 /**
+ * A Stormpath Factor Challenge Grant-specific Authenticator Factory.
+ *
  * @since 1.3.1
  */
 public interface OAuthStormpathFactorChallengeGrantRequestAuthenticatorFactory extends OAuthRequestAuthenticatorFactory<OAuthStormpathFactorChallengeGrantRequestAuthenticator> {