found by cppcheck
[src/Cedar/DDNS.c:656]: (style) Condition 'ret==NULL' is always true
[src/Cedar/DDNS.c:515] -> [src/Cedar/DDNS.c:640]: (style) The expression 'use_https == false' is always true because 'use_https' and 'false' represent the same value.
[src/Cedar/DDNS.c:516] -> [src/Cedar/DDNS.c:648]: (style) The expression 'no_cert_verify == false' is always true because 'no_cert_verify' and 'false' represent the same value.
[src/Cedar/DDNS.c:816] -> [src/Cedar/DDNS.c:860]: (style) The expression 'no_cert_verify == false' is always true because 'no_cert_verify' and 'false' represent the same value.
[src/Cedar/DDNS.c:530]: (style) Variable 'use_vgs' is assigned a value that is never used.
[src/Cedar/DDNS.c:497]: (style) The function 'DCUpdateNow' is never used.
- Hash() has been removed because it was ambiguous, Md5() and Sha0() are proper replacements.
- HMacMd5() and HMacSha1() now share a common implementation handled by the new Internal_HMac() function.
- NewMd() and MdProcess() now support plain hashing (without the key).
- NewMd(), SetMdKey() and MdProcess() now check the OpenSSL functions' return value and in case of failure a debug message is printed along with the error string, if available.
- SetMdKey()'s return value has been changed from void to bool, so that it's possible to know whether the function succeeded or not.
- MdProcess()' return value has been changed from void to UINT (unsigned int) and the function now returns the number of bytes written by HMAC_Final() or EVP_DigestFinal_ex().
