Port of addrindex patch https://github.com/jmcorgan/bitcoin/commit/4790f3c823a33fae44b82ef7962372e38b1b0131
Auxpow implementation
Auxpow: release reference to CReserveKey
Auxpow: blockdb upgrade message, chain ID method replaced with const
Merge remote-tracking branch 'origin/addrindex'
Added comments
Fixes to auxpow RPC
Fix to auxpow blockversion check
Tweaks to auxpow RPC, remove unused CReserveKey reference
Require reindex of pre-auxpow database, fix mis-requiring reindex of empty DB
Fix download link for gitian builds

Rebased-From: 164a45f57a8a7367e67a5e65b9e938844730cd87
Github-Pull: #5471
Merge branch 'auxpow' merged mining

This merge enables merged mining on testnet
Remove unused methods
version 0.9.99 -> 0.10.0

Bump version but keep CLIENT_VERSION_IS_RELEASE at false as this is not
a release yet.
Fix typo in searchrawtransactions RPC call name
Fix for auxpow mainnet blockversion check
Merge remote-tracking branch 'bitcoin/0.10'
add missing CAutoFile::IsNull() check in main

Rebased-From: 84857e87e42e412336ea60d0f8544c1679bab827
Github-Pull: #5437
Merge remote-tracking branch 'bitcoin/0.10'
Make CScriptNum() take nMaxNumSize as an argument

While the existing numeric opcodes are all limited to 4-byte bignum
arguments, new opcodes will need different limits.