The Wallet object used to have a guarenteed lifetime longer than the App
singleton, but then we started allowing people to delete their wallet
(argh!).
Also "external" modules, especially living outside of the main tree,
would be much more stable if they can avoid using raw pointers for core
concepts like the Wallet.
This fixes the general flow, but specifically adds two things:
1. we detect the lack of peers and notify the user of this problem with
an alarming looking screen.
2. We move to only requiring 1 peer to accept the transaction, since on
slow network connections the others tend to get it from each other
instead of me.
This separates it into two objects in order to make thead-safety easy
using Qt's signal/slot mechanism.
Additionally this removes magic timeout numbers and simply starts a
timer to check for changes and emit a signal if the status actually
needs updating.
Testing also shows that QML calls the getter a LOT, so I also moved the
broadcastStatus to be buffered and just return that on the call.
This incidentally also simplifies the code, double win.
tomFlowee