added some javadoc comments

src/main/java/com/inteligr8/github/http/PreemptiveAuthInterceptor.java

@@ -15,8 +15,24 @@ import org.apache.http.impl.auth.BasicScheme;
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.protocol.HttpCoreContext;
 
+/**
+ * This class allows the developer to force the sending of credentials on the
+ * first HTTP request.  Without this interceptor, all requests will first try
+ * without credentials.
+ * 
+ * A subsequent retry will happen only under certain HTTP status codes.  Some
+ * services will return a 404 instead of an expected 401 or 403.  This is for
+ * security reasons.  As a side effect, it fools the Apache HTTP client into
+ * thinking that the resource does not exist, even if it were authorized.  So
+ * it will not retry it with credentials.
+ *  
+ * @author brian@inteligr8.com
+ */
 public class PreemptiveAuthInterceptor implements HttpRequestInterceptor {
 
+	/**
+	 * @see HttpRequestInterceptor#process(HttpRequest, HttpContext)
+	 */
     public void process(final HttpRequest request, final HttpContext context) throws HttpException, IOException {
         AuthState authState = (AuthState) context.getAttribute(HttpClientContext.TARGET_AUTH_STATE);