Add reduced configuration used by picocoin
diff --git a/configs/config-picocoin.h b/configs/config-picocoin.h
new file mode 100644
index 0000000..c1ace1e
--- /dev/null
+++ b/configs/config-picocoin.h
@@ -0,0 +1,59 @@
+/*
+ * Reduced configuration used by Picocoin.
+ *
+ * See README.txt for usage instructions.
+ *
+ * Distinguishing features:
+ * - no SSL/TLS;
+ * - no X.509;
+ * - ECDSA/PK and some other chosen crypto bits.
+ */
+
+#ifndef POLARSSL_CONFIG_H
+#define POLARSSL_CONFIG_H
+
+/* System support */
+#define POLARSSL_HAVE_LONGLONG
+#define POLARSSL_HAVE_ASM
+#define POLARSSL_HAVE_TIME
+#define POLARSSL_HAVE_IPV6
+
+/* PolarSSL feature support */
+#define POLARSSL_CIPHER_MODE_CBC
+#define POLARSSL_CIPHER_PADDING_PKCS7
+#define POLARSSL_ECP_DP_SECP256K1_ENABLED
+#define POLARSSL_ECDSA_DETERMINISTIC
+#define POLARSSL_PK_PARSE_EC_EXTENDED
+#define POLARSSL_ERROR_STRERROR_DUMMY
+#define POLARSSL_FS_IO
+
+/* PolarSSL modules */
+#define POLARSSL_AESNI_C
+#define POLARSSL_AES_C
+#define POLARSSL_ASN1_PARSE_C
+#define POLARSSL_ASN1_WRITE_C
+#define POLARSSL_BASE64_C
+#define POLARSSL_BIGNUM_C
+#define POLARSSL_DES_C // ???
+#define POLARSSL_ECDSA_C
+#define POLARSSL_ECP_C
+#define POLARSSL_ENTROPY_C
+#define POLARSSL_HMAC_DRBG_C
+#define POLARSSL_MD_C
+#define POLARSSL_MD5_C // ???
+#define POLARSSL_OID_C
+#define POLARSSL_PADLOCK_C
+#define POLARSSL_PEM_PARSE_C // ???
+#define POLARSSL_PEM_WRITE_C // ???
+#define POLARSSL_PK_C
+#define POLARSSL_PK_PARSE_C
+#define POLARSSL_PK_WRITE_C
+#define POLARSSL_RIPEMD160_C
+#define POLARSSL_SHA1_C
+#define POLARSSL_SHA256_C
+#define POLARSSL_X509_USE_C // !!!
+#define POLARSSL_X509_CRT_PARSE_C // !!!
+
+#include "check_config.h"
+
+#endif /* POLARSSL_CONFIG_H */