Testnet - Double Doppler 4.2.8646

NOTE: In some cases, wallet can take up to 20 minutes for converting databases to the new format on the first start after update

Features:

• [desktop wallet] In one word: "notifications", in two: "decentralized notifications"! We did it right, the wallet address won't be exposed when any notification is received. The wallet will nicely tell you about transaction completion or when it's time to update the wallet to a new version. No worries, our wallet will never auto-update - this decision is entirely in your hands.
• [desktop wallet] Exchange rates to USD/BTC. Under the hood we use the same decentralized notifications infrastructure, hence again, your privacy stays solid.
• [api] Atomic Swap API for market-makers. Build your systems to manage decentralized atomic swap orders!
• [infrastructure] Wallet Identity was added to proof and ensure that transaction performs between claimed participants.
• [cli wallet] Laser beams for instantaneous BEAM transfer

Improvements:

• [desktop wallet] Payment proof added when transaction history is exported
• [desktop wallet] AddAll button when sending BEAM

Fixes:

• [desktop wallet] "Where to buy BEAM" button is back

Over 90 tasks accomplished in total, for more details please see here: https://github.com/BeamMW/beam/projects/25

Points to mention:

• In case a mobile wallet is connected to a random node and the user has both mobile and desktop wallets that are using the same seed phrase, the funds sent to the desktop wallet won’t appear on the mobile wallet. If the desktop wallet is running a local node, it will see funds sent to both wallets. The reason is that the local node (integrated into the desktop wallet) always monitors the blockchain for UTXOs related to the seed of the wallet. The mobile wallet does not run a local node and thus can only monitor transactions sent to its specific SBBS addresses. Of course, no funds will be lost in any event.