Revert "removed debug output"

This reverts commit 1f248637f9a9237927a63194876e300ba6566050.
working on payment-form: reversed order
added title tag to head, fixed bug in invoice form
improved invoice date functions
small improvement in payment forms
adding translations for actions, removed % from dist_man
switched payment date representation to timestamp
fixed bug: creation of new payments array for user
added some checks
smaller improvements
fixed bug in balance_man
some style changes