Address Index

[Liquid369]

With PIVX updating its Core with Bitcoin backports and the latest updates we can now also use Address indexing.
This PR will add the configuration options -addressindex, -timestampindex, and -spentindex

RPC method for retrieving utxo's:
getaddressutxos - which will return unspent outputs for any address or addresses

Example:

Mostly a cherry pick of whats left from bitpay#6

Done with the help of @Nugetzrul3

[Liquid369]

I see linter failed, but I noticed also since last night a lot of changes merged possibly causing my issue. I think I will need to rebase on master now. Let me know if I am correct, I tried to find the whitespace but nano/vim shows nothing in the error called out.