Meta server: set authenticated name to PSK key id in the case where no server PSK call back set, in order to make chunk server PSK authentication method work.
Kfsio library: store peer's psk id/hint in the case if no server psk was specified. Implement connection filter method to retrieve "peer's id".
Chunk server: make chunk server handshake error message more verbose by display failure reason communicated by the meta server.
Meta server: make chunk server PSK authentication work. Fix PSK with fixed key authentication logic. Remove extraneous ".tls" prefix with PSK authentication configuration parameters. Always require that the fixed PSK key specified by the configuration to be in base 64 format to match the client configuration logic. Change the meta server authentication logic to use meta server PSK key id as chunk server authenticated name, and chunk server PSK id hint as authenticated name in the case if the meta server psk key id is empty.
Annotated configuration files: add chunk server PSK authentication method parameters description. Remove PSK parameters extraneous ".tls" prefix.