Forgot to fix this occurrence of return value mismatch in
BIFArchive::ReadResource()
Fix implicit conversion
The template versions of Stream::Read() and ReadAt() don't return a
value or error anymore. They just throw an exception when reading
fails. The return value wasn't checked anywhere, anyway.
In the clean target, don't use rm -r *.o because it doesn't descend into
subfolders. Specify the subfolders explicitly. Also don't remove *~
files.