Restart-wallet fix

[crowning-]

Reference: https://dashtalk.org/threads/enhanced-darkcoin-wallet-ui.1705/page-24#post-58114

My wallet does not crash on Linux at all, and on Windows only about one out of 50 tries if I'm lucky, so it's really hard to test if this works reliably. Found out that almost all crashes are side effects of using BOOST, though, but it's used all over the place so we won't change that.

In theory, QApplication inherits quit() from QCoreApplication so it shouldn't make any difference, but since "Reset Options" uses QApplication::quit() to stop the wallet I thought I would give it a try.

So far (about 80 tries, even in the middle of reindexing) it looks good, however since the blockchain is stuck I can't test this while mining.

I'd appreciate others testing this while mining/mixing.

[UdjinM6]

That would be very odd but nothing is impossible I guess :)
I would however wait till we fix blockchain issues first.

[UdjinM6]

please test #395 on windows

[crowning-]

Added 2 more changes:
1: init.cpp: use a timed_lock of 10 secs (instead of try_lock) to check if another wallet is still running. This avoids a possible lockup if a user has a wallet running and tries to start 2 more wallets at the same time.

2: dash.cpp: ignore additional restart-wallet clicks. On windows you could easily click on a repair-wallet button fast enough to trigger more than 1 wallet-restart. Not good.

3: locally removed my own fix for #395, you were faster :-)

From my point of view we can merge this now to have more testers using it.

[UdjinM6]

Looks good 👍