will allow to submit some device benchmark data to compute algo
power usage and profitability.
Introduce two new methods mining.get_algo and mining_get_stats
These methods will be used with yiimp stratum with a special benchmark option
Note: only the first card is handled for the moment.
also add stratum mining.ping support (like cgminer 4.7.1+) and prevent disconnect
on unknown methods, reply it is unsupported.
Switching to a pool with a different algo will require a barrier
to free ressources, like what was made in the global benchmark.
add also the algo in pool structure...