GetAdminClient: get a new admin client.

NewLogClient: creates a new LogClient given a tree ID.

ReadAdminClientConfigFromFile: read admin client config from file.

ReadLogClientConfigFromFile: read log client config from file.

SaveAdminClientConfigToFile: save admin client's config to file.

SaveLogClientConfigToFile: save log client config to file.

TODO(yongzhe): termination of conn.

AdminClientConfig: configuration of the client.

LogClient represents a client for a given Trillian log instance.

LogClientConfig: config for a log client.

PoIAndSTH: contains Sign Tree Head and Proof of Inclusion for one leaf.

QueueRPCResult: result of queue a batch of RPC.