use new data file specification in form files

abrechnungReise/abrechnung.form

@@ -1,6 +1,6 @@
 
 ---
-Antrag-Path: antrag.form
+Antrag-Path: .
 Data: Antrag
 FieldName: Mainconfig
 Nonfield: True

antragReise/antrag.form

@@ -1,4 +1,11 @@
-
+---
+FieldName: Specifier
+Nonfield: True
+Default: d
+d-Value: Antrag
+Comment: "Antrag" (the specifier) is the name other form files can use to specify to use data from this form file.
+d-Comment: no Priority, should only be usable once completed.
+d-TODO: Somehow inform user that it is not to be used yet when aborted.
 ---
 Default: r
 Default: full