realloc like a boss, so checksum verification doesn't take minutes.
recode base64 hashes if necessary
save some memory by reducing buffer sizes
spell out base64 in error messages
let cpp do some of the work
fix the band-aid error.
tedu was bitten by the RETARDED interface in sha2.h (who names string LENGTH
things that are actually buffer SIZES) ?
make -C mode work again.

okay beck@