This change adds a hook for the BlockChecked signal to the zmq
publisher. This is useful for light wallet daemon initialization.
The new flag is `-zmqpubcheckedblock=address`
- removes mapBlockIndex find operation
- theoretically allows removing the cs_main lock during zqm notification while introducing a new file position lock
Continues Johnathan Corgan's work.
Publishing multipart messages
Bugfix: Add missing zmq header includes
Bugfix: Adjust build system to link ZeroMQ code for Qt binaries
Daira Hopwood