Add OpenSSL error logging at every location where serf returns error SERF_ERROR_SSL_COMM_FAILED.
Add OpenSSL error logging at every location where serf returns error
SERF_ERROR_SSL_COMM_FAILED.

* buckets/ssl_buckets.c
  (log_ssl_error): New function.
  (ssl_decrypt, ssl_encrypt): Add logging in case of I/O error.

yesoce/serf,stoneCC/serf,lazysoez/serf,SirJson/serf,google-code-export/serf,yesoce/serf,x-clone/serf,x-clone/serf,pengdu/serf,zhupan/serf,soufianeEL/serf,zhupan/serf,alex1818/serf,soufianeEL/serf,stoneCC/serf,SirJson/serf,yesoce/serf,x-clone/serf,zhengcq315/serf,pengdu/serf,soufianeEL/serf,KyleSanderson/serf,lazysoez/serf,zhengcq315/serf,pengdu/serf,zhengcq315/serf,google-code-export/serf,pengdu/serf,google-code-export/serf,KyleSanderson/serf,google-code-export/serf,lazysoez/serf,lazysoez/serf,x-clone/serf,alex1818/serf,yesoce/serf,stoneCC/serf,KyleSanderson/serf,SirJson/serf,zhengcq315/serf,zhupan/serf,alex1818/serf,KyleSanderson/serf,SirJson/serf,stoneCC/serf,soufianeEL/serf,alex1818/serf,zhupan/serf