Split AssFile into separate lists for each section
Remove some cruft from TextFileReader
Make the entry lists be of the appropriate type rather than just AssEntry

Eliminates a bajillion dynamic casts.
Change AssFile::Info to a vector
Don't return a const std::string from GetData

It has zero benefit and forces an extra copy.
Remove AssEntry::Clone
Move the intrusive list hooks to the concrete entry types
Devirtualize AssEntry::GetEntryData
Make AssFile::Attachments a vector
Fix non-pch compilation
Do disgusting things to make LuaAssFile work

LuaAssFile relied on the lifetime guarantees of intrusive lists (i.e.
you can pretty much do whatever the fuck you want and it'll work out),
but AssInfo objects are no longer owned by an intrusive list. Do awful
things to lazily copy the header section when needed to provide similar
lifetime guarantees.
Silence some warnings from boost.crc
Update deps
Kill the awkward automatic subtitle format (de)registration