removed std namespace from header

git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/slim/trunk@162 7c53e7cc-98ea-0310-8f1f-a0b24da60408

app.h

@@ -90,7 +90,7 @@ private:
 
     void blankScreen();
     Image* image;
-    void setBackground(const string& themedir);
+    void setBackground(const std::string& themedir);
 
     bool firstlogin;
     bool daemonmode;