Fixes per Vigilant Sentry (http://www.vigilantsw.com/)

* Fix memory leaks.

* Add comments about initializations and checking for successful results.

* Add checks for NULL deref.

* Consistency in "TODO" vs "TO-DO" comments!

src/import/Import.cpp

@@ -282,7 +282,11 @@ void Importer::WriteImportItems()
       gPrefs->Write (name, val);
    }
    /* If we had more items than we have now, delete the excess */
-   for (i = this->mExtImportItems->Count(); i >= 0; i++)
+   // ANSWER-ME: Vigilant Sentry notes i is unsigned so (i >= 0) is always true. 
+   //    If that's what you want, why not make the condition just be "true"? Or should it be an int?
+   //    But also, it looks like it's supposed to be a down-counting loop, so is i++ correct?
+   //    Rather, shouldn't i be set to this->mExtImportItems->Count() each time?
+   for (i = this->mExtImportItems->Count(); i >= 0; i++) 
    {
      name.Printf (wxT("/ExtImportItems/Item%d"), i);
      if (gPrefs->Read(name, &val))

src/import/ImportFLAC.cpp

@@ -467,13 +467,16 @@ int FLACImportFileHandle::Import(TrackFactory *trackFactory,
    useOD=true;
 #endif
 
-#ifdef LEGACY_FLAC
-   bool res = (mFile->process_until_end_of_file() != 0);
-#else
-   bool res = true;
-   if(!useOD)
-      res = (mFile->process_until_end_of_stream() != 0);
-#endif
+   // ANSWER-ME: Vigilant Sentry: Variable res unused after assignment (error code DA1)
+   //    Plus, it's not even declared in the LEGACY_FLAC clause
+   //#ifdef LEGACY_FLAC
+   //   bool res = (mFile->process_until_end_of_file() != 0);
+   //#else
+   //   bool res = true;
+   //   if(!useOD)
+   //      res = (mFile->process_until_end_of_stream() != 0);
+   //#endif
+
    //add the task to the ODManager
    if(useOD)
    { 

src/import/ImportMIDI.cpp

@@ -53,6 +53,7 @@ bool ImportMIDI(wxString fName, NoteTrack * dest)
    if(new_seq->get_read_error() == alg_error_open){
       wxMessageBox( _("Could not open file ") + fName + wxT("."));
       mf.Close();
+      delete new_seq;
       return false;
    }