Implement new /changes/{id}/action style REST API

All existing JSON APIs are converted to this new style.

/changes/{id} parses the id field from a JSON response from a prior
response and uses that to uniquely identify a change and verify the
caller can see it. If the user requests only /changes/{id}/ then the
data is returned as a single JSON object.

This commit also gives full remote control of plugins using the
/plugins/ namespace:

  PUT /plugins/{name}    (JAR as request body)
  POST /plugins/{name}   (JSON object {url:"https://..."})
  DELETE /plugins/{name}
  GET /plugins/{name}/gerrit~status
  POST /plugins/{name}/gerrit~reload
  POST /plugins/{name}/gerrit~enable
  POST /plugins/{name}/gerrit~disable

The commit provides some project admin commands:

  GET /projects/{name}/description
  PUT /projects/{name}/description

  GET /projects/{name}/parent
  PUT /projects/{name}/parent

Project dashboards have moved:

  GET /projects/{name}/dashboards
  GET /projects/{name}/dashboards/{id}
  GET /projects/{name}/dashboards/default

To access project names containing /, the name must be encoded with
URL encoding, translating / to %2F.

Change-Id: I6a38902ee473003ec637758b7c911f926a2e948a

gerrit-server/src/main/java/com/google/gerrit/server/project/SetParent.java

@@ -0,0 +1,106 @@
+// Copyright (C) 2012 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.project;
+
+import com.google.common.base.Objects;
+import com.google.common.base.Strings;
+import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.DefaultInput;
+import com.google.gerrit.extensions.restapi.ResourceConflictException;
+import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
+import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.config.AllProjectsName;
+import com.google.gerrit.server.git.MetaDataUpdate;
+import com.google.gerrit.server.git.ProjectConfig;
+import com.google.gerrit.server.project.SetParent.Input;
+import com.google.inject.Inject;
+
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.errors.RepositoryNotFoundException;
+
+class SetParent implements RestModifyView<ProjectResource, Input> {
+  static class Input {
+    @DefaultInput
+    String parent;
+    String commitMessage;
+  }
+
+  private final ProjectCache cache;
+  private final MetaDataUpdate.Server updateFactory;
+  private final AllProjectsName allProjects;
+
+  @Inject
+  SetParent(ProjectCache cache,
+      MetaDataUpdate.Server updateFactory,
+      AllProjectsName allProjects) {
+    this.cache = cache;
+    this.updateFactory = updateFactory;
+    this.allProjects = allProjects;
+  }
+
+  @Override
+  public Class<Input> inputType() {
+    return Input.class;
+  }
+
+  @Override
+  public Object apply(ProjectResource resource, Input input)
+      throws AuthException, BadRequestException, ResourceConflictException,
+      Exception {
+    ProjectControl ctl = resource.getControl();
+    IdentifiedUser user = (IdentifiedUser) ctl.getCurrentUser();
+    if (!user.getCapabilities().canAdministrateServer()) {
+      throw new AuthException("not administrator");
+    }
+
+    try {
+      MetaDataUpdate md = updateFactory.create(resource.getNameKey());
+      try {
+        ProjectConfig config = ProjectConfig.read(md);
+        Project project = config.getProject();
+        project.setParentName(Strings.emptyToNull(input.parent));
+
+        String msg = Strings.emptyToNull(input.commitMessage);
+        if (msg == null) {
+          msg = String.format(
+              "Changed parent to %s.\n",
+              Objects.firstNonNull(project.getParentName(), allProjects.get()));
+        } else if (!msg.endsWith("\n")) {
+          msg += "\n";
+        }
+        md.setAuthor(user);
+        md.setMessage(msg);
+        config.commit(md);
+        cache.evict(ctl.getProject());
+
+        ListProjects.ProjectInfo info = new ListProjects.ProjectInfo();
+        info.setName(resource.getName());
+        info.parent = project.getParentName();
+        info.description = project.getDescription();
+        return info;
+      } finally {
+        md.close();
+      }
+    } catch (RepositoryNotFoundException notFound) {
+      throw new ResourceNotFoundException(resource.getName());
+    } catch (ConfigInvalidException e) {
+      throw new ResourceConflictException(String.format(
+          "invalid project.config: %s", e.getMessage()));
+    }
+  }
+}