Vcs: Add Fossil SCM integration plugin

* Qt Creator base-commit: f77af5e336
* Stand-alone plugin source tree for integration into qtc super-project
* Original release: https://github.com/nomadbyte/qtcreator-plugin-fossil
* Adapted from Bazaar plugin implementation

Configuring Fossil
------------------

1. Download the [Fossil SCM client](http://fossil-scm.org) and install `fossil`
   executable file in your `PATH`.

2. Create or designate a directory to store local Fossil repositories and
   remote clones. For example: `~/fossils/qt`.

3. Configure Version Control Options for the Fossil plugin to use
   the designated directory as `Local Repositories Default path`.

Now Fossil should become available as a VCS choice to create new local
repositories, as well as a choice in `New File or Project` to clone a
remote Fossil repository.

Change-Id: I630184c1b344184d9e08ae2fc24a5e4766f834b9
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

plugins/fossil/pullorpushdialog.h

@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (c) 2016 Artur Shepilko
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <QDialog>
+
+namespace Fossil {
+namespace Internal {
+
+namespace Ui { class PullOrPushDialog; }
+
+class PullOrPushDialog : public QDialog
+{
+    Q_OBJECT
+
+public:
+    enum Mode {
+        PullMode,
+        PushMode
+    };
+
+    explicit PullOrPushDialog(Mode mode, QWidget *parent = nullptr);
+    ~PullOrPushDialog() final;
+
+    // Common parameters and options
+    QString remoteLocation() const;
+    bool isRememberOptionEnabled() const;
+    bool isPrivateOptionEnabled() const;
+    void setDefaultRemoteLocation(const QString &url);
+    void setLocalBaseDirectory(const QString &dir);
+    // Pull-specific options
+    // Push-specific options
+
+protected:
+    void changeEvent(QEvent *e) final;
+
+private:
+    Mode m_mode;
+    Ui::PullOrPushDialog *m_ui;
+};
+
+} // namespace Internal
+} // namespace Fossil