*** 1.3.37 (Martin Hecht: 24-Mar-2021)
fix two array to string conversions in paintform
make export of sumissions more stable with respect to field indices
suppress warning when saving settings with email from name settings
fix warnings about internal quoting function
support export of selected submissions
support deleting selected submissions
make export more stable with old results table data structure
insert submission_id in results table during import and when submitting
add possibility to change separator for csv file in export
