[FIX] Fixed potential PPLNS issue

* getMinimumShareId did not use Share Counts but Weights
[FIX] Fixing PPS calculations

* [FIX] PPS estimations
* [FIX] PPS Value, PPS Payouts being off (too low)

Tested on testnet, estimates worked perfectly and payouts worked well.
[FIX] 14 and 30 days estimates
[UPDATE] Proper implementation of target bits

* [ADDED] New Config Option: Algorithm
 * scrypt and sha256d supported right now
 * might add SHA coin support across MPOS
 * Compatible with previous implementation
* [REMOVED] config option: pps_target
 * Replaced by config option: algorithm
 * Please update your config, defaults to srypt now!
* [ADDED] Unpaid Shares in Dashboard
* [MODIFIED] User estshares from DB query instead template math
Merge branch 'next' into payout-fixes
[FIX] Dashboard API on non-PPS system
Revert "[FIX] Fixed potential PPLNS issue"

This reverts commit ee46e65fcae431da852240fb2a13e7f3f29b30e6.
[FIX] Proper fetch Archive Shares

Is now in-line with getMininumShareId.
[IMPROVED] Adding pools specific PPS rate

* Show Diff1 Baseline PPS Rate
* Use pools set minimum difficulty to display pool based rate
Merge pull request #764 from TheSerapher/payout-fixes

Payout fixes