crypter: add tests for crypter

Verify that results correct (match known values), consistent (encrypt->decrypt
matches the original), and compatible with the previous openssl implementation.

Also check that failed encrypts/decrypts fail the exact same way as openssl.

src/Makefile.test.include

@@ -94,6 +94,7 @@ BITCOIN_TESTS += \
   wallet/test/wallet_test_fixture.h \
   wallet/test/accounting_tests.cpp \
   wallet/test/wallet_tests.cpp \
+  wallet/test/crypto_tests.cpp \
   wallet/test/rpc_wallet_tests.cpp
 endif