WIP: tech controller and tech setup dialog

Some bug fixes (description was not updated in tree,
base path of new tech was not set, dirs were not reused
for new tech).

Some enhancements (tech setup dialog's window state
is persisted etc.)

src/laybasic/layAbstractMenu.cc

@@ -873,7 +873,6 @@ AbstractMenu::build (QToolBar *t, std::list<AbstractMenuItem> &items)
     }
 
   }
-
 }
 
 QMenu *

src/laybasic/layQtTools.cc

@@ -103,6 +103,10 @@ save_dialog_state (QWidget *w)
 void 
 restore_dialog_state (QWidget *dialog, const std::string &s)
 {
+  if (! dialog) {
+    return;
+  }
+
   tl::Extractor ex (s.c_str ());
 
   while (! ex.at_end ()) {