The command to render old messages now looks for all messages
not matching the bugdown version, and it no longer directly calls
into model code. We should still be extremely cautious about
using this code.
This pulls message-related code from models.py into a new
module called message.py, and it starts to break some bugdown
dependencies. All the methods here are basically related to
serializing Message objects as dictionaries for caches and
events.
extract_message_dict
stringify_message_dict
message_to_dict
message_to_dict_json
MessageDict.to_dict_uncached
MessageDict.to_dict_uncached_helper
MessageDict.build_dict_from_raw_db_row
MessageDict.build_message_dict
This fix also removes a circular dependency related
to get_avatar_url.
Also, there was kind of a latent bug in Message.need_to_render_content
where it was depending on other calls to Message to import bugdown
and set it globally in the namespace. We really need to just
eliminate the function, since it's so small and used by code that
may be doing very sketchy things, but for now I just fix it. (The
bug would possibly be exposed by moving build_message_dict out to the
library.)