Fixed problem with None user on history take_snapshot
WIP: Fix an error in the attachment serializer class
WIP: Fix an error with the USs creation in bulk
WIP: Make a refactor of the bullk creation actions
WIP:
WIP: Fix some freezer functions
WIP:
WIP
Adding markdown service
Adding emoji post procesor
WIP
WIP
Adding description_html and content_html to us, task, issue and wiki history freezers
WIP
Adding mdrender tests for all procesors and fixed references procesor