hashcash: change available-chars to a constant.
hashcash: change available-chars to a constant.

factor/factor,tgunr/factor,tgunr/factor,factor/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,tgunr/factor,mrjbq7/factor,factor/factor,factor/factor,tgunr/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,mrjbq7/factor,factor/factor,factor/factor