Added certificate creation using ECDSA

* dtls/test/makecerts_ec.bat: creates ca-cert_ec.pem, keycert_ec.pem and server-cert_ec.pem
* dtls/test/openssl_ca.cnf and openssl_server.cnf: Added HOME to be able to use the conf file under windows

dtls/test/certs/ca-cert_ec.pem

@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----
+MIIBgzCCASoCCQDdMwvUA/R3lzAKBggqhkjOPQQDAzBKMQswCQYDVQQGEwJVUzET
+MBEGA1UECAwKV2FzaGluZ3RvbjETMBEGA1UECgwKUmF5IENBIEluYzERMA8GA1UE
+AwwIUmF5Q0FJbmMwHhcNMTcwMzA3MDgzNjU3WhcNMjcwMzA1MDgzNjU3WjBKMQsw
+CQYDVQQGEwJVUzETMBEGA1UECAwKV2FzaGluZ3RvbjETMBEGA1UECgwKUmF5IENB
+IEluYzERMA8GA1UEAwwIUmF5Q0FJbmMwWTATBgcqhkjOPQIBBggqhkjOPQMBBwNC
+AASD4xiQkPryjEwUl/GYeGu1CSA3UC6BUY3TiGED3zrC5Bn/POaVVn9GGOQMZUFi
+rCkuTgfg/qeIzTrTFndiR5C/MAoGCCqGSM49BAMDA0cAMEQCIHpd9qMvZZV6iaB5
+HrmlyfmhIuLBxDQra20Uxl2Y8N64AiAmPKqwPPp7z6IT2AzAXyHCPoVxwWA0NfGx
+nmXoYpDFlw==
+-----END CERTIFICATE-----

dtls/test/certs/keycert_ec.pem

@@ -0,0 +1,19 @@
+-----BEGIN EC PARAMETERS-----
+BggqhkjOPQMBBw==
+-----END EC PARAMETERS-----
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIEMWCku4TqKwrQdeECm5LQPCBnr7+cqE4InlRYeObLOxoAoGCCqGSM49
+AwEHoUQDQgAEgroFe2fym1V7E3zr/zjuJixpyAjwfig+UTsxxm/04IvXzk2jQCQC
+TgbDVohJ8dgh4iEENZv2axWye7XCBzbftQ==
+-----END EC PRIVATE KEY-----
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

dtls/test/certs/server-cert_ec.pem

@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----