IT gh#797

#797 Zoom does not open new document

Testcase to check if creating Credit Memo from Invoice opens the correct window

1. Create new sales invoice, and a product and complete it
   • => there are 2 new buttons: one for credit memo and one for adjustment charge
2. create new credit memo from the button, select a doctype (do not select complete it), press ok
   • => new credit memo is created and opened in a new window
   • => on the first invoice the credit memo button is readonly
3. repeat steps 1 and 2 for the other doctypes from credit memo
   • => works the same
4. create a new sales invoice, add a product and complete it
   • => there are 2 new buttons: one for credit memo and one for adjustment charge
5. press on create adjustment charge button and select a doctype, press ok
   • => new adjustment charge is created and opened in a new window
   • => on the first invoice the adjustment charge button is readonly
6. repeat steps 4 and 5 for the other doctypes from credit memo
   • => works the same