Show height and hash in block ACCEPTED message.
Add algo to ACCEPTED block message.
Show extra debug output in Reorganize().

In Reorganize(), show old, new and common fork point in the debug output
log information.
Add getchains RPC command.

Implement a new "getchains" RPC command, that returns all heads of
blockchain forks known.
Add branch info to getchains.

Add additional result fields to getchains output that show the branches
connecting the heads to the main chain.
Merge pull request #18 from domob1812/extra-output

Show algo of blocks in debug log.
Merge pull request #19 from domob1812/rpc-get-chains

Implement getchains RPC command.