Fix Watchonly: cs_main lock not held
Fixed error in 'getbalance' when using watchonly addresses.
Add boolean HaveWatchonly and signal NotifyWatchonlyChanged

Conflicts:
	src/qt/overviewpage.cpp
	src/qt/walletmodel.cpp
	src/qt/walletmodel.h
[Qt] Add column Watch-only to transactions list

Conflicts:
	src/Makefile.qt.include
	src/qt/transactiontablemodel.cpp
	src/qt/transactionview.cpp
[Qt] minor watch-only changes

- use watch-only, not watchonly
- add back a tooltip hint when hovering addresses and attach
  "(watch-only)" at the end
[Wallet] Watch-only fixes

Conflicts:
	src/qt/transactionrecord.cpp
	src/rpcwallet.cpp
	src/wallet.h