Bitcoin Wrapper improvements

* [FEATURE] Allow for PoS/PoW Detecion in getdifficulty
* [FEATURE] Allow for SHA detecion in getnetworkhashps
* [IMRPOVEMENT] Added caching for bitcoin values (30s only)
 * Will reduce the amount of RPC calls for high load pages
use new bitcoin method wrapper for public API
use bitcoin wrapper method for getdiff calls
Merge branch 'next' into issue-444-theserapher