Electron Cash Released with CoinShuffle

RELEASE 4.0.0
Privacy features have been added, most notably CashShuffle has been integrated strongly into the wallet. It is an optional plugin for shuffling coins securely with other users. Coin control and other logic has been added as well. The bulk of the work for this release has been this feature. (Clifford, cculianu, Josh Ellithorpe, Mark Lundeberg, Jonald Fyookball, imaginaryusername, emergent_reasons, acidsploit, and others).
Fix #1174, #1178 - Resurrection of .onion support (requires enabling of non-SSL).
Fixups for qr code image saving (cculianu), #1175
Closing a wallet now actually closes its daemon threads. Closing a wallet window now also implicitly closes any tx dialog child windows it created. Closing the last wallet window in the app will quit the app, even if other child windows are still alive. (cculianu)
Coins tab layout fixups #1180, including right click -> Copy X (cculianu, Mark Lundeberg, SomberNight)
Addition of Wallet -> Scan beyon gap... tool #1194 (cculianu)
Fixed #968 for the Receive tab -- when the form is unsaved it now always is guaranteed to refresh itself with a new unused address in real time. (cculianu)
Tx notification systray popup was too intermittent. It now pops up more frequently when reeiving or synching a new wallet. The wording used has also been simplified. (cculianu)
Fix #1182 - Bad proxy can end up in config file (cculianu)
Fix #1215 - Tabs that are not being shown are no longer refreshed in the GUI. They refresh themselves when you switch to them, however, if they need to. This should improve perception of UI responsiveness for large wallets especially. (cculianu)
Fixed some bugs related to switching chains (forks) #1185 (cculianu)
Fixed a bug where importing a private key didn't update the history until app restart. (cculianu)
Fix Network Dialog layout (SomberNight)
Fix sign message not accept rich text spesmilo#5210 (SomberNight)
Fix #1189 - Cope better with unknown wallet formats or corrupt wallets on startup. This should improve the experience for SLP users that also use regular Electron Cash (cculianu)
Switch over to bitcoin-abc libsecp in preparation for Schnorr signatures. Libsecp is now actually bundled with the Linux "source" tarball. (cculianu)
Fix to exchange rate prefs screen UI and deletion of BitcoinAverage as a historical rate provider (cculianu)
If running from source, app now has an icon on all platforms (cculianu)
Fix ubuntu installation for virtual-env (acidsploit)
Due to phishing being a recurrent annoyance, "Preferred servers only" now defaults to "CHECKED" for new installs. (cculianu)
Many performance improvements, especially for large wallets (cculianu)
Cache address balance in memory rather than recompute each call (SomberNight)
Various internal bugfixes (cculianu, SomberNight, ecdsa)