WIP: next hard fork

[BrannonKing]

This hard fork achieves the following changes:

• [x] Claims never expire
• [x] Restrictions on claim names will be enforced as part of block validation (as now they are only enforced in the mempool).
• [x] Some current delay computation bugs will be bypassed.
• [x] Claims on the empty name will not be included in the trie hash (and won't be bid-provable).
• [x] The trie hash function will change to include name, bid, sequence, and ClaimID, enabling full proof on any of those.
• [x] Proof RPC calls will be added to go with the new hash function.
• [ ] Claim delay calculations will use original height rather than last update height?
• [ ] Possible: Trie hash computations will switch to single SHA256 instead of double SHA256?
• [ ] Possible: full support for timelocked utxos?
• [ ] MinFeePerNameclaimChar will go away.
• [ ] 8k bytes name+data cap should go to 12k?

[coveralls]

Pull Request Test Coverage Report for Build 1225402214

• 35 of 304 (11.51%) changed or added relevant lines in 11 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.05%) to 30.225%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
blockchain/validate.go	0	1	0.0%
claimtrie/merkletrie/merkletrie.go	0	2	0.0%
claimtrie/node/node.go	8	10	80.0%
claimtrie/node/manager.go	1	7	14.29%
claimtrie/node/hashfunc.go	0	47	0.0%
claimtrie/merkletrie/ramtrie.go	0	48	0.0%
rpcclaimtrie.go	0	52	0.0%
blockchain/claimtrie.go	0	53	0.0%
claimtrie/node/hashfork_manager.go	0	58	0.0%
<!--	Total:	35	304

Totals
Change from base Build 1225378357:	-0.05%
Covered Lines:	12571
Relevant Lines:	41592

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💛 - Coveralls