tools/crypto_bench: add CAST5 support

Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: James Almer <jamrial@gmail.com>
avformat/matroskadec: Fix cluster parsing loop which gathers seek information

Fixes Ticket2263
Fixes Ticket3934

Reviewed-by: Rodger Combs <rodger.combs@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>