Support of REST API "block" for the coins with old APIs.

[tokusyu]

As you have already implemented, getblock JSON PRC has 2 versions.
Old one doesn't support verbose option, you need to call getrawtransaction RPC to get transaction data.

As long as I know, REST API "blocks" with ".json" extension returns transaction data even if the Coins don't support verbose option on their JSON RPC.
https://github.com/bitcoin/bitcoin/blob/master/doc/REST-interface.md#blocks

How about supporting REST API "block"?
I know it is not elegant, but it has an advantage on speed.

To make REST API enable, you need add args "-rest" with your bitcoind.

[medvedev1088]

I didn't know about the REST API, thanks for informing. Definitely worth taking a closer look.