debuged some horrible race conditions & deadlocks

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@160 0fc631ac-6414-0410-93d0-97cfa31319b6

src/gui/thumbnail_thread.hpp

@@ -48,7 +48,6 @@ class ThumbnailRequest {
 class ThumbnailThread {
   public:
 	ThumbnailThread();
-	~ThumbnailThread();
 	
 	/// Request a thumbnail, it may be store()d immediatly if the thumbnail is cached
 	void request(const ThumbnailRequestP& request);
@@ -58,6 +57,7 @@ class ThumbnailThread {
 	/// Abort all thumbnail requests for the given owner
 	void abort(void* owner);
 	/// Abort all computations
+	/** *must* be called at application exit */
 	void abortAll();
 	
   private: