Add a id() method to projects

* This makes it easier to distinguish projects in the
   userfileaccessor

src/plugins/cmakeprojectmanager/cmakeproject.cpp

@@ -441,6 +441,11 @@ QString CMakeProject::displayName() const
     return m_projectName;
 }
 
+QString CMakeProject::id() const
+{
+    return QLatin1String("CMakeProjectManager.CMakeProject");
+}
+
 Core::IFile *CMakeProject::file() const
 {
     return m_file;

src/plugins/cmakeprojectmanager/cmakeproject.h

@@ -75,6 +75,7 @@ public:
     CMakeBuildConfiguration *activeCMakeBuildConfiguration() const;
 
     virtual QString displayName() const;
+    virtual QString id() const;
     virtual Core::IFile *file() const;
     virtual ProjectExplorer::IBuildConfigurationFactory *buildConfigurationFactory() const;
     virtual CMakeManager *projectManager() const;