Hand history explanation should fit the PS format

[anisoptera]

Currently PPN "explains" hand histories in its own format, and the history is written to the DB only in the raw internal format. We do the parsing in our frontend, which is not robust and causes high load on the server.

Instead, PPN should be able to "explain" this history in the PokerStars HH format, and possibly cache this in the database for user requests.