[OEM-258] added method to OphTrOperationbooking_API and wrote a bunch of tests for the class.
[OEM-255] made waiting list letters print using the new PDF system.
[OEM-255] admission letter
[OEM-255] made admission letter/form work with the new PDF printing system.
[OEM-255] refactored a bit
[OEM-255] output buffering is unnecessary here
[OEM-255] use the new wkhtmltopdf margins
Merge branch 'jira/OEM-258'
updated release
Merge branch 'master' into feature/glaucoma-2.1