Sort more imports and wrap documentation at 100 columns.

This is a mechanical refactoring. The only thing I had trouble with is IntelliJ's
weak support for `<ul>` tags in Javadoc.

samples/guide/src/main/java/okhttp3/recipes/AsynchronousGet.java

@@ -15,12 +15,12 @@
  */
 package okhttp3.recipes;
 
+import java.io.IOException;
 import okhttp3.Callback;
 import okhttp3.Headers;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
 import okhttp3.Response;
-import java.io.IOException;
 
 public final class AsynchronousGet {
   private final OkHttpClient client = new OkHttpClient();