IVersionControl: Add method to get a ShellCommand for initial checkouts

Change-Id: Iabc056dad186d788003b221afb34303c37fef728
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/mercurial/mercurialcontrol.h

@@ -64,6 +64,11 @@ public:
     bool vcsCreateRepository(const QString &directory) override;
     bool vcsAnnotate(const QString &file, int line) override;
 
+    Core::ShellCommand *createInitialCheckoutCommand(const QString &url,
+                                                     const Utils::FileName &baseDirectory,
+                                                     const QString &localName,
+                                                     const QStringList &extraArgs) override;
+
     bool sccManaged(const QString &filename);
 
 public slots: