VCS: Add id to IVersionControl

... and all derived classes

src/plugins/bazaar/bazaarcontrol.cpp

@@ -34,6 +34,7 @@
 #include "bazaarclient.h"
 
 #include <vcsbase/vcsbaseclientsettings.h>
+#include <vcsbase/vcsbaseconstants.h>
 
 #include <QtCore/QFileInfo>
 #include <QtCore/QVariant>
@@ -52,6 +53,11 @@ QString BazaarControl::displayName() const
     return tr("Bazaar");
 }
 
+QString BazaarControl::id() const
+{
+    return QLatin1String(VCSBase::Constants::VCS_ID_BAZAAR);
+}
+
 bool BazaarControl::managesDirectory(const QString &directory, QString *topLevel) const
 {
     QFileInfo dir(directory);