Added

• TLS support

  --tls verify server with CA certificates installed on this system
  --tls-insecure do NOT verify server (accept any certificate)
  --tls-cafile value verify server with CA certificate stored in specified file
  --tls-capath value verify server with CA certificates located under specified path

• Windows build

Changed

• --timeout option now affects both dialing to server and RPC call (before that dialing had hard-coded 1s timeout)
• more descriptive messages are printed out in case of failure

Added

• Probing servers and services via gRPC health-checking protocol