workspace view colors based upon variable scope (derived from Dan's patch #8013) * resource-manager.cc/.h(storage_class_names): function returning scope names (storage_class_colors): function returning default colors for scopes (storage_class_chars): function returning the ident. characters of the scopes * color-picker.cc(constructor): prevent focus for the colored pushbutton * settings-dialog.cc/.h(read_workspace_colors): function reading the colors from the setitngs and creating a table with color-pickers in the settings dialog (write_wirkspace_colors): function getting the states of the color-pickers and writing them into the settings files * settings-dialog.cc(constructor): call read_workspace_colors (write_changed_settings): call write_workspace_colors * settings-dialog.ui: new tab for workspace settings with a box for the colors * workspace_model.cc/.h(notice_settings): reading colors from the settings * workspace-model.cc(constructor): initialize list of colors (data): reorganize determining the appropriate data and take background color role into consideration * workspace-model.h(storage_class_color): returns the color for a specific scope * workspace-view.cc/.h(notice_settings): create tool tip with color key (setModel): not inline anymore, actual model is stored in _model