Add extended headers

They don't yet have the right type associated with them.
Use right types

I think I have everything figured out. Still deciding how much the
extended fields should be used. They're more unstable and of
questionable value. I will skip them for now but leave the definitions
for if/when they get added.
Import cwgame_event_dtype

Time to start parsing events. This will take some processing power and
storage considering how many millions of events there are.