Mercurial: Show current branch in project tree and window title

Task-number: QTCREATORBUG-11388

Change-Id: I55c966b5026e435d0fa4d24607b7b4a3c6d9e3dc
Reviewed-by: Nikita Baryshnikov <nib952051@gmail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/mercurial/mercurialcontrol.cpp

@@ -136,6 +136,11 @@ bool MercurialControl::vcsAnnotate(const QString &file, int line)
     return true;
 }
 
+QString MercurialControl::vcsTopic(const QString &directory)
+{
+    return mercurialClient->branchQuerySync(directory);
+}
+
 bool MercurialControl::sccManaged(const QString &filename)
 {
     const QFileInfo fi(filename);

src/plugins/mercurial/mercurialcontrol.h

@@ -65,6 +65,7 @@ public:
     QString vcsGetRepositoryURL(const QString &directory);
     bool sccManaged(const QString &filename);
     bool vcsAnnotate(const QString &file, int line);
+    QString vcsTopic(const QString &directory);
 
 public slots:
     // To be connected to the HgTask's success signal to emit the repository/