Add support for setting each of these attributes on a per RPC call basis to sendtoaddress, sendmany, fundrawtransaction (already had RBF), and bumpfee (already had RBF and conf target).
GetMinimumFee now passes the conservative argument into estimateSmartFee.
Call CalculateEstimateType(mode) before calling GetMinimumFee or estimateSmartFee to determine the value of this argument.
CCoinControl can now be used to control this mode.
No change in behavior. Get rid of specifiedConfirmTarget if/else block and
rename specifiedConfirmTarget and ignoreUserSetFee variables to
ignoreGlobalPayTxFee.
```
$ git blame src/policy/fees.cpp | grep becuase
3810e976 (2017-03-07 11:33:44 -0500 789) * checks for 2*target becuase we are taking the max over all time
$ git blame src/policy/fees.h | grep successfullly
2d2e1705 (2017-04-12 12:29:03 -0400 54) * representing that a tx was successfullly confirmed in less than or equal to
$ git blame src/wallet/feebumper.cpp | grep "hasen't"
a3878374 (2017-05-11 09:34:39 +0200 258) // make sure the transaction still has no descendants and hasen't been mined in the meantime
```
Marko Bencun