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
use wrapper to fetch last network block
adding cold wallet coin display and setting
Also show negative cold coins

Fixes #660
[IMPROVEMENT] Adding incremental round/user shares

This will address #510. It needs thorough testing and is a WiP but
is a start to improve cron runtime and DB loads.
[IMPROVEMENT] Support incremental contrib shares
Merge pull request #661 from TheSerapher/issue-510

Issue 510
use archive table for sharerate calcs
[BUG] Fixing contrib shares issue without cache
[MERGE] Merge conflict NEXT