Implement the KW and KWP algorithm

1. Add kw to the Makefiles
2. Implement the algorithms as defined in SP800-38F, and RFC 3394.
diff --git a/library/Makefile b/library/Makefile
index b1597e0..ac88d4c 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -76,11 +76,11 @@
 		hkdf.o						\
 		hmac_drbg.o	md.o		md2.o		\
 		md4.o		md5.o		md_wrap.o	\
-		memory_buffer_alloc.o		oid.o		\
-		padlock.o	pem.o		pk.o		\
-		pk_wrap.o	pkcs12.o	pkcs5.o		\
-		pkparse.o	pkwrite.o	platform.o	\
-		platform_util.o	poly1305.o			\
+		memory_buffer_alloc.o		nist_kw.o	\
+		oid.o		padlock.o	pem.o		\
+		pk.o		pk_wrap.o	pkcs12.o	\
+		pkcs5.o		pkparse.o	pkwrite.o	\
+		platform.o	platform_util.o	poly1305.o	\
 		ripemd160.o	rsa_internal.o	rsa.o  		\
 		sha1.o		sha256.o	sha512.o	\
 		threading.o	timing.o	version.o	\