Directly use config objectnor make templated version in input filters

Following up from a comment by @pzejdl in the !24 (merged) discussion:

> Optional:
> Because the config object is passed as a reference, I think it is probably not necessary create to create member's variables for scone explicitly. One can also use `conf.getSconeHost()`... when calling reset_board.
> 
> In fact, we can also create an overloaded (or templated if we want to keep in the header) version accepting the conf object directly. I can propose something.