Added support for Rijndael (aka AES).

Rev: src/modules/_Crypto/Makefile.in:1.25
Rev: src/modules/_Crypto/crypto.c:1.39
Rev: src/modules/_Crypto/crypto.h:1.6
Rev: src/modules/_Crypto/include/rijndael.h:1.1
Rev: src/modules/_Crypto/lib/Makefile.in:1.26
Rev: src/modules/_Crypto/lib/configure.in:1.10
Rev: src/modules/_Crypto/lib/rijndael-boxes.dat:1.1
Rev: src/modules/_Crypto/lib/rijndael.README:1.1
Rev: src/modules/_Crypto/lib/rijndael.c:1.1
Rev: src/modules/_Crypto/rijndael.c:1.1