result of get_db_path should be a part of ClientConfig

[debris]

I'm opening it up for discussion. Currently get_db_path is used in config, client

ethcore/src/client/client.rs:111:pub fn get_db_path(path: &Path, pruning: journaldb::Algorithm, genesis_hash: H256) -> PathBuf {
ethcore/src/client/client.rs:130:       let path = get_db_path(path, config.pruning, spec.genesis_header().hash());
parity/configuration.rs:29:use ethcore::client::{append_path, get_db_path, ClientConfig, Switch, VMType};
parity/configuration.rs:188:            let db = journaldb::new(&append_path(&get_db_path(Path::new(&self.path()), *i, spec.genesis_header().hash()), "state"), *i);

and another one time in migration code in this pr https://github.com/ethcore/parity/pull/1014

We could simplify it by making db_path part of the config.

[gavofyork]

seems reasonable.

[debris]

fixed in cli_overhaul #1600 (not merged yet)

[rphmeier]

in the #1679, i alter get_db_path to accept the path with the genesis hash already appended, so it really just figures out what the path should be based on pruning