project: detect project version and show errors on incompatibility

app/task/project/save/save.cpp

@@ -25,6 +25,7 @@
 #include <QXmlStreamWriter>
 
 #include "common/filefunctions.h"
+#include "core.h"
 
 OLIVE_NAMESPACE_ENTER
 
@@ -49,7 +50,9 @@ bool ProjectSaveTask::Run()
 
     writer.writeStartElement("olive");
 
-    writer.writeTextElement("version", "0.2.0");
+    // Version is stored in YYMMDD from whenever the project format was last changed
+    // Allows easy integer math for checking project versions.
+    writer.writeTextElement("version", QString::number(Core::kProjectVersion));
 
     project_->Save(&writer);