add preference for disabling workspace colors for different attributes * gui-preferences.h: add new and mive existing preferences for the workspace view * settings-dialog.cc (settings_dialog, write_changed_settings): remove use of workspace prefs here; (read_workspace_colors): construct all elements of the workspace tab by code instead of the designer file; (write_workspace_colors): store the values of the check boxes for workspace preferences * settings-dialog.h: add check boxes of workspace view, that are removed from the designer file and now constructed in the code, as class variables; * settings-dialog.ui: clear the workspace tab, all elements are now constructed and laid out in the the code * workspace-model.cc (data): set background color only if attribute colors are desired * workspace-model.h: new class variable holding whether colors are used or not * workspace-view.cc (notice_settings): use constants from gui-preferences.h for key names and default values instead of hard coded values and store preference for using attribute colors

--- a/libgui/src/workspace-model.h	Sat Oct 27 06:54:47 2018 -0400
+++ b/libgui/src/workspace-model.h	Sun Oct 28 20:31:08 2018 +0100
@@ -111,6 +111,7 @@
     QStringList m_columnNames;
 
     QList<QColor>  m_storage_class_colors;
+    bool m_enable_colors;
 
   };
 }