Correct import and export for isotag1

Importing with option isotag1=3000 for non-marc iso files resulted in invisible additional fields in the database. This commit is solves this for non-marc databases. For marc databases the export is enhanced but the import needs additional work. In all files…

Improve feedback iso export and import

The working folder might be protected somehow. Feedback was insufficient. Test for is_executable works for linux but not for windows. Detailed modifications: – exporta_txt_ex.php: improved access test+ show footer on second screen+translations for fixed strings – vmx_import_iso.php: Improved access test…