Add options to /changes/<id>/detail

Clients fetching the detailed information about a change need more
than just the labels, they also expect to see the current revision and
data from its commit.  Support the o/O options used by /changes/ to
permit clients to obtain more information than the default set.

Change-Id: Ic8f910474b8f13e6faf76199c5781a38075380ac

Documentation/rest-api-changes.txt

@@ -364,6 +364,11 @@ Retrieves a change with link:#labels[labels], link:#detailed-labels[
 detailed labels], link:#detailed-accounts[detailed accounts], and
 link:#messages[messages].
 
+Additional fields can be obtained by adding `o` parameters, each
+option requires more database lookups and slows down the query
+response time to the client so they are generally disabled by
+default. Fields are described in link:#list-changes[Query Changes].
+
 .Request
 ----
   GET /changes/myProject~master~I8473b95934b5732ac55d26311a706c9c2bde9940/detail HTTP/1.0

gerrit-server/src/main/java/com/google/gerrit/server/change/GetDetail.java

@@ -19,9 +19,21 @@ import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 
+import org.kohsuke.args4j.Option;
+
 public class GetDetail implements RestReadView<ChangeResource> {
   private final ChangeJson json;
 
+  @Option(name = "-o", multiValued = true, usage = "Output options")
+  void addOption(ListChangesOption o) {
+    json.addOption(o);
+  }
+
+  @Option(name = "-O", usage = "Output option flags, in hex")
+  void setOptionFlagsHex(String hex) {
+    json.addOptions(ListChangesOption.fromBits(Integer.parseInt(hex, 16)));
+  }
+
   @Inject
   GetDetail(ChangeJson json) {
     this.json = json