bugfix release: pshell import and preview

changes:
- catch runtime errors due to empty datasets
- improve window titles and graph names
- fix scaling of scienta image from XPSSpectrum script
- remove unnecessary spaces and underscores from folder names

pearl/pearl-data-explorer.ipf

@@ -1450,7 +1450,7 @@ static function bp_dataset_folder(ba) : ButtonControl
 				string cmd
 				sprintf cmd, "setdatafolder root:%s", PossiblyQuoteName(dataset)
 				execute /q /z cmd
-				cmd = "setdatafolder :scan_1"
+				cmd = "setdatafolder :scan1"
 				execute /q /z cmd
 				sprintf cmd, "setdatafolder %s", GetDataFolder(1)
 				print cmd