BitShares Core Release 2.0.180205

@oxarbitrage release this on...

Note:

Security fixes

BSIP27: OP for issuer to reclaim fee pool funds #188
BSIP30: Disallowed increasing debt when updating short position (BSIP30 part 2) #827, #672
BSIP35: Mitigate rounding issue when matching orders #830
- cherry-picked from #641, including changes related to #132, #184, #342 and BSIP35: Mitigate Rounding Issue On Order Matching
BSIP36: Clear expired feeds on maintenance interval #889
- New PR for issue: #518, refactored from PR #832
- Clean up bitasset_data during maintenance #518
BSIP37: Allowed new asset name to end with a number (BSIP37) #705, #620
Implements BSIP31-34: Market engine #641,#184, #59, #829, #830, #338 #343 #453 #606 #625 #649
Implement BSIP26: Refund order creation fee in original paid asset when order is cancelled #604
- Implement BSIP26 Refund original fee #627
- Replaces #623. PR for #604
Implement BSIP38: add target CR option to short positions #834
- This is PR for #834 (BSIP38: add target_cr option to call order #834)

Fixed: Black swan detection checks short position with lowest call_price but not lowest collateral ratio #649
Fixed: Clear price feed data after updated a bitAsset's backing asset ID #868
Fixed: Inconsistent sorting of call orders between matching against a limit order and a force settle order #343
Fixed: In asset_update_bitasset_evaluator::do_apply() - Should update median feeds after feed_lifetime_sec changed #890
Fixed: Margin call order fills at price of matching limit_order but not at a price related to itself or settlement_price #338
Fixed: Multiple limit order and call order matching issue #453, #537
Fixed: Potential erratic order matching issue involving margin call orders #625
Fixed: Potential something-for-nothing fill bug #184, #338.#342, #505
Fixed: Rounding issue when matching orders #342
Fixed: Unable to propose a proposal with an approve_proposal operation #214, #658, #492
Fixed: Undercollateralized short positions should be called regardless of asks #606, #625, #641
Fixed: Updated median feeds after feed_lifetime_sec changed #891 #904 (PR for #890. Based on #901)
Fixed: Virtual operations should be excluded from transactions #588
- PR #591

Allowed updating a call order to higher collateral ratio #655, #583
Asset claim pool operation #572
Asset update issuer operation #599
Cleaned feeds at maint time #598
Cleaned up HF409 related code #712
Created more test cases for BSIP35 #883
Fixed #214 #841
- Revised HF protection for #214 with additional test scenario #857
Fixed #588 Virtual operations should be excluded from transactions #698
Fixed for Issue 868 - Reset feeds when changing the backing asset from one asset to another #882
- Clear price feed data after updated a bitAsset's backing asset ID #900 (PR for #868)
Reviewed and tested something-for-nothing check #132, #338, #342