Add rpc command 'getunconfirmedbalance' to obtain total unconfirmed balance

Conflicts:
	src/rpcserver.cpp
Remove -logtodebugger

`-logtodebugger` is a strange, obscure, WIN32-only (mostly MSVC) thing.
Let's clean up the options a bit get rid of it.

test_bitcoin was using fLogToDebugger as a way to prevent logging to
debug.log. For this, add a boolean (not exposed as option) fLogToDebugLog that
defaults to true and is disabled in the tests.
qt: Treat regtest as testnet

No need to do anything special in the GUI for regtest mode,
but do treat it at testnet not mainnet to prevent confusion.
Merge pull request #3437

2ea980a qt: Treat regtest as testnet (Wladimir J. van der Laan)
Merge pull request #3369

6027b46 Add rpc command 'getunconfirmedbalance' to obtain total unconfirmed balance (Michael Bauer)
Merge pull request #3416

9e9056c Remove -logtodebugger (Wladimir J. van der Laan)
init: add better formating for some command-line options
[Qt] coin control change address handling update

- re-work change address handling so that default is CNoDestination(),
  until a verified and known change address was entered (easier code flow)
- add a missing NULL pointer check for adresstablemodel
- add a missing text when opening coin control address selection for
  priority and ensure the label is black
- add a missing . at the end of a sentence
Merge pull request #3439

3c95599 init: add better formating for some command-line options (Philip Kaufmann)
Merge pull request #3391

3380713 [Qt] coin control change address handling update (Philip Kaufmann)
qt: make wallet test consistent

Add a function `WaitBlocks` to wait for blocks to propagate to all three
nodes, and use this instead of waiting a fixed time of one second.

Fixes #3445.
Merge pull request #3451

5fe19d6 qt: make wallet test consistent (Wladimir J. van der Laan)