AUP3: Reduce crash exposure when compacting

There's still the possibility if a crash happens at just the
right time that the project will be named "<project>_compact_back"
so we should probably look for it during startup.

This also changes all "Vacuum" references to "compact".

src/DBConnection.cpp

@@ -68,6 +68,11 @@ bool DBConnection::Open(const char *fileName)
    }
 
    // Set default mode
+   //
+   // NOTE: There is a noticable delay here when dealing with large multi-hour projects
+   //       that were just created with "Save As". Presumably this is because of the
+   //       journal mode switch from NONE to WAL. Should it be wrapped in a progress
+   //       dialog?
    SafeMode();
 
    // Kick off the checkpoint thread