If the function that extracts/computes the public key from a private key
fails the errors it reports were masked by the function calling it. This
patch modifies the key extraction function to return errors using
_libssh_error() function. The error messages are tweaked to contain
reference to the failed operaton in addition to the reason.
* AUTHORS: - add my name
* libgcrypt.c: _libssh2_pub_priv_keyfile(): - return a more verbose
error using
_libssh2_error() func.
* openssl.c: - modify call graph of _libssh2_pub_priv_keyfile() to use
_libssh2_error for error reporting();
* userauth.c: - tweak functions calling _libssh2_pub_priv_keyfile() not
to shadow error messages
I went over the NEWS and git log outputs and added all mentioned
contributors through the project's history. I want us to make an
effort to give credit to everyone who contributes, big or small.
