don't use shared ptr on projects

Really unnecessary

app/task/project/save/save.cpp

@@ -29,7 +29,7 @@
 
 namespace olive {
 
-ProjectSaveTask::ProjectSaveTask(ProjectPtr project) :
+ProjectSaveTask::ProjectSaveTask(Project *project) :
   project_(project)
 {
   SetTitle(tr("Saving '%1'").arg(project->filename()));

app/task/project/save/save.h

@@ -30,9 +30,9 @@ class ProjectSaveTask : public Task
 {
   Q_OBJECT
 public:
-  ProjectSaveTask(ProjectPtr project);
+  ProjectSaveTask(Project* project);
 
-  ProjectPtr GetProject() const
+  Project* GetProject() const
   {
     return project_;
   }
@@ -41,7 +41,7 @@ protected:
   virtual bool Run() override;
 
 private:
-  ProjectPtr project_;
+  Project* project_;
 
 };